I know the T-1 and T-2 areas can be crazy. But how much room are you given to the next guy? Do you have to fight for space? Can you sit down to put your shoes on? Need to know if I should bring my Martial Arts experience with me on race day ..LOL
I have never had a problem especially if it is open racking. Odds are you won't be next to the person anyways. The only time it is an issue is if you have assigned racks and it is a TT swim start based on times. Then realistically you both could get out of the water together and to your bikes at the same time.
You give the other guy as much space as the RD allots him. If there are to be seven bikes on the rack (standard for the local tris) you take exactly 1/7 of the space on the rack.
You can sit if you want. Here's a recent thread discussing the pros and cons: