I use /script AcceptBattleFieldPort(1,1) I think. That is pretty close, it lets you in the BG.
They used to make the largest group the BG leader so you can arrange your guys, but that changed recently and not sure if they will change it back. Not sure what to do about that, sorry. I think, maybe, just maybe, you can move people if you are promoted, might try that. It might be easier to get promoted, over getting leader.

I use /script RepopMe() to accept the release option when you die.

I can't really fix the not res together part. Couple of ideas. Try to get your group together or fail-die. Either meet in the middle (2 from one place head to the 3 from the other and they meet in the middle so all together again). Or send some to meet with the others (2 at stables, 3 at GM, send the 2 from stables to GM by using click to move---one BIG click super far away). Or you can just send the stragglers to die close to where you want them to res. It doesn't help the game much, but you getting back together probably helps more and maybe you pull 2-3 away from a place to chase you down and make an opening to take a place which never hurts. People love to run away from defense to chase down lone people.

I use Jamba (or Multiboxer) to accept resses auto-magically.
You can turn off the messages for "out of range" "spell not ready" etc. It is in the comms section. Not sure since I don't have it in front of me.