No need to worry about bugs, no. Actually bugs are good. (I really wanted to put "mmmmmkayyyy" after that, like the guidance counsellor from South Park

) If you really get into the natural enclosures, youll actually find yourself buying bugs to put in there.
What you do with the plants will depend on what kind of animal you are putting them in with, to a certain extent. I usually take them out of the pot they come in, get rid of some of the dirt around the roots and then give the whole thing a good spray rinse. That'll get any pesticides off that they might have sprayed on them. (Dont spray all the dirt off the roots, but give the top of the plant itself a good spray.)