re portlight bedding:
I have done both butyl and Life-Calk (or similar, not 5200) and will always use caulk in the future.
Dry fit portlight in place and line exterior periphery with blue painters' tape.
Fill the flange with copious caulk, intending plenty of excess inside and out.
Press in place. The caulk should fill all gaps and the interior overflow will be hidden by the inside trim.
Tighten the interior trim, but recall that it is only cosmetic and no great force is required (which will only bend it anyhow).
The exterior painters' tape makes exterior cleanup easy.
Caulk fills gaps, butyl doesn't. Gaps are intentional, since the boat flexes. Caulk, not adhesive, is correct because portlights have to withstand only pressure from the outside, which is handled by the flange.
If there are issues with teak damage, more
here.