1) My NC is a steady 81.5-82.7. I think 84 is a tad on the high side. If you know how do DIY better fans, that sounds cool.
2) If the snails are stuck and holding on, they are alive. They might be a little 'shocked' but they should be OK
3) No...a common misconception and mistake among nano reefers. People add corals to their nano tank, they fluorish initially. Then they add fish and food and with it comes fish poop and detritus and nitrates. Then the post, "Help, my corals are dying".IMO, no nano tank should have corals in it for weeks after cycling if not months. If you plan on keeping fish, you have to get a feel for nitrate control, ie, nutrient import and export. It is my recommendation to all new nano reefers to GO SLOW and DO NOT ADD CORALS until your tank is stable. Avoid the 'plunk maneuver' (chucking in corals right after your tank cycles). Don't forget, your next visitor might be cyanobacteria and hair algae. Hopefully not.
4. Digital camera..should be standard equipment. ???Asterinas?, but, they don't multiply like crazy.
5. Don't dose your new tank. It is immature. Keep up with 10% weekly water changes.
SH