I just got my new 55 gal tank for my garters.... and i have a few questions.....

1. the temps right now arfe 90 hot side 80 cool side.... is that too warm???
2. is a 55 gal big enough for 4 adult snakes? (3 females, 1 male)
3. there is a light inside the cage, should i be woried about them climbing on it and getting burned?
4. is it ok to have a live plant in there? i have no idea what kind it is.....

pics will com soon/eventually.... have to clean my room first lol