I'll start by saying a major argument advanced by some CT advocates for the scattershot tech/government/cultural nature of the sectors we see comes from:
a) A model whereby the Imperium is very far off as a government except in a few very limited ways and they don't care much to interfere in local governance (and one would think that might include parts of trade and system business)
b) That trade is limited in scope and tends to be high value items often not intrinsically valuable (luxury stuff)
c) That the Imperium may well be in decay and that may explain much of the sort of fallen, lagging or problematic polities we see
d) The Imperium was NOT built up over a day and different sectors and different systems got different deals with the Imperium meaning you might well have to bend on that whole 'no taxes' thing if you want to get some high pop planets or ones with strong governments and high tech into your early Imperium and those precedents would echo into later absorption deals
Then we have those that look more at a GT - integrated, fleshed-out, complete, and more orderly - model...
a) Large trade volumes
b) A strong central government that does allow some local authority and autonomy, but does have a big footprint (large fleets, many organizations, strong control of trade, etc) and a certain uniformity across known space
c) A strong focus on active trade (presumably to drive revenues in some way not requiring direct taxation of movement of goods? I call this the 'Step 1: Take control of trade, Step 2: ?, Step 3: Credits for the Imperium' plan)
d) The Imperium in that setting does not feel fallen, does not feel decayed, and trade is in every sort of commodity not just luxury goods
e) However, the corollary of that totality would be a more likely lean to more uniformity between polities (because they have a lot of trade and that trade is strongly regulated), between cultures and would serve to even out tech levels and government approaches more than we actually observe in any generations maps I've ever looked at (I think this is a problem - GT kept the broken systems/sectors while having thought out an Imperium that would tend to drag up general tech/government standards just as a side effect of large trade
f) Their universe does explain all sorts of counter-insurgencies and coups and so on given the strictures imposed by the Imperium and thus the Marines would get more work as would the Army
IMTU: I tend to run in a cross between the GTU and the Classic OTU (CTU? LBBTU? BBBTU?). However, I take a bunch of ideas from quite a few versions of the OTU.
A few ideas that I run with:
In order to be a part of the Imperium, it is practice that you must have an Imperial Starport. All traffic in and out of a world must pass Imperial customs. Normally, PC's will not even be aware of that - as the tariffs and fees are paid by the brokers or shippers. When the PC's leave the starport they enter into local law, and leave Imperial law. When they buy stuff 'On World' generally it's automatically sent to their ship, and the customs are subsumed into the price. If they can carry it past the XT line, then it's generally not valuable enough for the Imperium to really care.
So, do you have a 'formal' starport at every significant (and possibly insignificant) station or world in a system? Or does anyone jumping in have to be boarded or show up for inspection directly to the single mainworld starport? Does the Navy chase around anyone trying to sneak around to unload where the mainworld port is not their destination?
Sounds to me too if I read this right that there ARE taxes on goods in your TU. (They makes historical and political sense to me).
Now, the Imperium is a large place, and this ideal is not always 100% followed, especially on the fronteer. But that's the theory. Practice can vary wildly, until someone with the juice to fix it notices. Things can (and do) vary wildly from one extreme to the other.
Does the Imperium in your TU try to arm twist new candidates to accept the SPA and cede all interstellar (and maybe intra-system) trade? Is this a per world negotiation or does the Imperium just show up with a very immutable standard agreement and say 'take it, leave it, or maybe we'll even just invade'?
An Imperial starport might be a modular cutter's starport module on a flattened field, or it might be a highport/low port complex.
Security is either handled by Navy, COACC or Marines, (Enri, why did you get posted *here*?) or the lone SPA offical's shotgun.
Dagnabit! Now I have Sean Connery and Outland on the mind.
Who handles customs inspections and assessments (versus security inspections)? Imperial Forces instead of system forces?
Armed Forces:
Navy - Controls space (duh). Transports. Intelligence.
Marines - Boarding actions, and establishing beachheads. Also loaned to Star Port Authority.
Army - Expands beach heads, defends worlds. COACC is a branch of the Army, as is the Wet Navy.
I'd be diplomatic and classify forces into 'Planetary Defense Services' and 'Space Services'. Really, there's no logic to Army owning Air Force or Navy or either of the other owning their siblings. Just lump them in under Planetary Defense and each get to have an 'element' General and they all report to the Planetary Marshal. I guess I know how sensitive who is the senior service discussions are in most militaries.
Scouts - Commo, Exporation, Research Stations, Black Ops. Extra-border Intelligence.
Civilian Forces:
Ministry of Justice - Hunts down Imperial Fugitives. Imperial Law, Lawyers, Runs prison ships and plants.
Why do they run plants? Is that somehow like running guns? Or was that prisons? (I'm being funny, but I also don't know what sort of 'plants' IMOJ would be running?
Star Port Authority - Runs Imperial start ports. Space Traffic Control (and Approach control). SAR in system, with Naval help.
The problem I have with the military doing this job is what my friend (Lieutenant-Commander RCN) reported from Afghanistan. He lamented that the forces there at Kandahar should stop giving lip service to CIMIC/CMA projects ('hearts and minds') because most senior military officers are only trained in kinetic operations and they were no good at conceiving and executing 'hearts and minds' work. He said they should let NGOs do that and we would protect them and stick to what said senior officers understood - BSU (Blowing S*** Up).
The mission profile for a combat ready navy is not the mission profile of a search and rescue and customs regime. If you optimize for one, you get lousy at the other.
This is one strong argument of a System Guard construct (to do boardings, law enforcement, and to support customs/immigration inspections). They can be paramilitary and some help during wartime in system security, but largely they don't need to be full fledged combatants (in terms of ship construction, but also in terms of how they approach every boarding).
Ministry of Finance - Taxes, Money Banking, Corporate Law. Imperial Currency. And Intelligence.
I had a good think about Imperial Money a while back and wrote something about it for my TU. I tried to make sense of money in a multi-system environment with every world perhaps having one or more local currencies and the issues surrounding trade and exchange processing (and costs). Also how a 'credit card' might actually work system to system.
Ministry of Research - Works closely with the Scouts - Hard Science
Diplomatic Core - Talk to people about doing things the Imperium wants them to do. Also Intelligence.
All of these groups have many arms, which might be competing with other group's arms. For example, all of them have an intelligence branch. Add in that Megacorps have similar branches, often working with or at odd of the Imperial groups, and it can get pretty wild out there.
This I think would always happen in a large bureaucracy.
There is a theory that Cleon created these working groups in order to balance them against each other, however that would have taken some prescience.
Not balance as in "I know all the players and I am balancing all of those known players one vs. another in all combinations" but more balance as in "we create many smaller players with some overlap but none gigantic and they will naturally tend to try to avoid oligopolies or monopolies". Of course, this was before we knew that big businesses would collaborate and lobby in very similar ways company to company to see that competition for medium to large companies isn't and that a virtual oligopoly can continue.
The really cool thing about the GURPS Traveller books is the authors (and playtesters) took the time to read through (at the time) 20+ years of contradictory canon, work through the consequences of that canon, and design in depth a consistent whole. The problem with that is it may not be the Imperium you know or want to have.
+1 I feel that the GTU was really the high point of the OTU, when taken alone.
Agree. If this was not tied to anything before or after, it would be a definitive thing all on its own and a well integrated one (except for some of the oddities they could not repair).