I will be wearing a wetsuit and I've swam in it 3 times - pool. Initially I thought it was too small because I was close to needing a larger size (chest area restrictive) but the last time I swam in it I felt more comfortable. A trick I learned was after getting in pool I pulled on neck to put water into suit then I was able to adjust it more easily and make it feel less restrictive. I bought it from Xterra and talked to them about fit - they recommended I stay with current size. Definitely different to swim in, didn't like it the first two times but by the third I was singing it's praises...

Right -flood it and adjust, then get out again to shed the water - I found myself carrying a gallon of water round my belly (mine isn't very snug)

Not sure what you mean? By appropriate gear do you mean running shoes so I can run/walk to the finish after racking my bike? I've watched videos of previous events and read posts and it seems there is some distance to get to finish - some people commented that it was confusing and they had done events before. The transitions worry me the most because I don't have a clue what they're like.

You can run to finish in your bike shoes . they might even have mats or carpeting (or the finish line might be before you rack) - no time lost changing into shoes.

Transition: as soon as you get out of the Water, start undoing the Zipper and getting out of the suit - pull down to the hips on the run. Practice getting out of the legs by standing on the suit, lookup a video. The longer you wait the more it sticks. I often get close to a cramp getting out...