It will destroy pump on long run when you leave breaker on. City water has higher pressure than pump can provide and it simply pushes water against flow what pump is designed for. Other boat manufacturers ( like Formula Boats) designed their system differently and allow for tank to be filled...
Once you remove window make sure you clean frame and fiberglass very good. You may want to scuff fiberglass with 320 sandpaper. Wipe frame and glass with acetone or alcohol. Use good quality marine grade silicone. I actually prefer this sealant instead silicone...
It is pita to put it over the edge of the platform 1without damaging top edge of the molding. Preferably preheat small sections to soften the vinyl. Once softer, bend vinyl 90 degrees or more and that will allow for u-shaped gap to open wider and to be slipped over fiberglass. Work in short...
Just short screws to grab fiberglass. Nothing really stick to that vinyl on the long run and you may want to be able to repair it when you the swim platform
Depends on the year there was trim installed. Factory installation used #6 ½" long screws (screws installed from the back of the trim).
https://www.fpmarine.com/U-shaped-motorbox-trim-p/uchannel%20trim%20pltfrm%20mtrbox%20wh.htm
They are probably plastic fasteners holding it in place ( i think sea ray calls them xmas tree fasteners). Removing them may cause old vent to break or break off piece holding faster in place. You may consider using stainless screw to reattach corner (do it on both sides so looks factory)...
Before you dive to reach float switch make sure that fuse or breaker are ok. Depends on float switch installed you may be able to lift it with coat hanger or something similar
It is all about length and how high antenna is located. Longer, higher - better range. Also antenna should be vertical to sea level to get optimum range.