rooney77 wrote:
I was going to see if cleaning all the crappy caulk off and tightening things would button it back up and then re-caulk it.
Can't tell too much about the vent until I get the cover off of it.
I would suggest totally cleaning the roof and skylight of all caulk and putting on fresh caulk. Otherwise there could be a problem with the old sealant and new caulking sealing properly, since you don't know what's been used before. After removing all the caulk, it's not that big a deal to remove the skylight to look for any issues in the opening.
As for the black tank vent you shouldn't see much after removing the vent cover, since all it does is cover and seal the whole in the roof, where the vent pipe protrudes, which naturally could be a source of any ceiling leak. I'd suggest cleaning the roof area around the vent pipe also and installing a new vent cover - they're cheap enough to just install a new one.