Aluminum TTT - Fitting/Mounting Door and Crank Out Windows

While I am working on my build thread, hoping to get some feedback on what I'm working on today - fitting the door and windows. (NOT riveting them yet)
-to fit snug or not to fit snug? any advantages to making the fit larger than the frames?
-can I continue to seal with sikka-seal, or is this vhb tape way better? or both?
I have these nice drip ledges (aluminum, curves at both ends) I got from Lil' Bear store, but forgot to order one for the door - I'm hoping to find another one to complete the look. Can you still get these somewhere?
I'm going to research this forum for mounting information - specifically looking for experience on what NOT to do.
-to fit snug or not to fit snug? any advantages to making the fit larger than the frames?
-can I continue to seal with sikka-seal, or is this vhb tape way better? or both?
I have these nice drip ledges (aluminum, curves at both ends) I got from Lil' Bear store, but forgot to order one for the door - I'm hoping to find another one to complete the look. Can you still get these somewhere?
I'm going to research this forum for mounting information - specifically looking for experience on what NOT to do.