80 is OK for the pepper plant and should be for the others as well. It would be nice if the temps dropped a little when the lights are not one though. Your plants can all expect daytime temps in the 80's and higher during the summer so 80 should be fine in the box. And I suggest you water based on need rather than a set schedule. Peppers do well when they are allowed to get nearly dry between waterings. They don't like constant moisture.
Bruce