I'm going to assume that all ships are automated for the sake of this thread but I don't know how they all operate or their AI behaves. I know you can put them in a fleet and how that works, so i'm ok with that. It's just individual ship behaviour. Please amend as necessary.
Escort - Guards planets and escorts ships around
Frigate - Patrols bases and planets, sometimes escorts ships
Destroy - Patrol bases and planets
Cruiser - Patrol bases
Capital Ship - ?
Carrier - ?
Explorer - explore

Colony - colonise... etc
Now I have a question about AI bases too as I want to build multirole stations, but something isn't working right. I've wanted to build a single base at a gas planet to mine and research, but run into issues. I don't know what to categorise it as. I tried mining, and noticed I didn't get the research bonus even with a lab on it. I tried a research base with extractors on and no-one turned up to get the goods. In the end I had to settle for both. I think I tried a Starbase in the past, but again no-one turned up for the goods (although of course as a fuel station it just mined it anyway and horded it for the military).
Starport - receives location bonuses (aka resort or research), receives and gives out freight, does not receive passengers for resort bases.
Starbase - receives location bonuses, does not trade freight (ie: does not sell mined goods). does not receive passengers. Does not automatically receive stock of goods for
Research stations - receives location bonuses, no passengers or trade
Mining Station - No location bonuses (for research), does not receive passengers, does trade stuff out.
Resort Base - receives passengers, gets location bonus (for resort), does not trade anything out ie: mining extractors won't sell their wares or be collected.
etc etc. Please shed some light on this.
Also one final question. Is it possible to reserve goods/cargo? Sometimes I want atleast a stash of fuel at a depot, but want to sell the excess. Is this possible? I know it's possible to build a starbase and no-one turns up, but you can mine the goods and then build a mining station anyway separately.