No, actually you shouldn't have any trouble seeing the freshly varnished areas at all. The reason is that you never varnish over shiny fiberglass. The old, peeling varnish should be removed (sanded off is easiest on the outside) and the resin surface should be sanded down to about 100 grit in order to get a decent varnish bond to the glass. By that time it will be nearly opaque white and will turn back to clear when the new varnish hits it. Resin is much harder than varnish, so though sanding off varnish is somewhat tedious, chances that you'll go through it and chop up the glass are minimal. A good random orbit machine and a box of 100 grit disks would be the best tools for the job and it should only take a couple hours of sanding to get the outside varnish-free and ready for any needed repairs and revarnishing.
If you want a decent looking finish, "skim coating" with resin isn't it. Resin doesn't go on and smooth-out the way paint and varnish do. It needs to be allowed to cure, sanded smooth and then varnished or painted or your surface will look like crap. Standard procedure would be to prep-sand the old resin (80-120 grit) and roll on a minimum of two thin coats of epoxy, then sand them smooth (again, 80-120 grit, which will likely remove most of one of those coats) and finally, varnish for UV protection and gloss.
Unless you have something strange going on, or large areas to repair, there really shouldn't be any reson to be applying more resin to the surface as a whole in the first place. Cracks should be re-fiberglassed (spot repairs with cloth and resin) and any delams should be cut out and spot repaired with new glass work. Resin alone is too brittle for fixing cracks or any sort of serious break in the covering. It will re-crack the first time you put the boat in the water and walk around in it. Those spots need the added strength of the fiberglass cloth. If you haven't worked with fiberglass much, you would be wise to pick up one of the books on stripper building. The process for fiberglassing (or repairing) the outside of this boat would be the same. For bad spots, you would be sanding and tapering out the old glass around the break, applying new glass cloth, filling its weave with additional coats of resin, sanding it smooth to match its surroundings and finally, re-varnishing the hull. I don't think you'll have much luck trying to inject resin into any delam spots that are big enough to matter. It's one of those options that sound good on paper, but don't go too well when you actually get around to trying it.
Most chemical strippers don't do an awful lot to cured fiberglass, so stripping the inside isn't likely to cause big problems. What can be a problem is soaking the area with water in the rinse phase of the stripping process. Wet, expanding wood on one side and fiberglass on the other don't get along well. Find a stripper that can be rinsed off with solvents, like mineral spirits, rather than water. They will still soak the wood a bit, but they evaporate out faster and a solvent wipe-down process wets the surface a lot less than blasting it with a garden hose.
