Hoi
1. Yeah, pretty much all automated and takes care of itself. You just might want to keep an eye on the security (The automated trade-fleets might get shot down, which will result in penalties) No Micro-management here (thank god), you just have to be the "Big-Idea-Guy"
2. Your colonies will contract mercenaries, spawn independents/smuggler or own trading fleets as it's able too. Other factions, which are in good standing, do send convoys too. If you have your own Heavy industries you can redirect the production to build ships for you... i am unsure if that impedes your automated fleets at all.
Have fun