I have sat on my top to spy mahi when trolling past pot markers. I think you'll be good standing up there on the troll as long as its flat and there are no big wakes...
I have done cannon balls jumping off the top
Definitely put in some BIG zipper smiley windows on the side and I suggest a zipper windshield panel at the windshield door rather than a smiley.
My three sides stay on all the time and I don't have a rear enclosure.
When I bought the boat it had a bimini full enclosure. I couldn't stand it in the summer. The rear piece stayed like new in the dock box until the bimini was crap, then it all got thrown out.