I just did some gel coat repair on my Wenonah Rendezvous, which is also labeled Kevlar 49. There were a couple places near the stems that had chunks missing, and I filled those with gel coat. There are three sets of spider cracks. I have used Captain Tolley's Creeping Crack Cure on the spider cracks. Tolley's is a thin, white liquid that is supposed to penetrate and seal cracks. I had never heard of this stuff and have no idea how effective it is, but it is real easy to apply. You might consider using it on your circles.
Advice provided by others, above, seem reasonable. The crack in photo #1, you've got to fix that one. If it's solid, gel coat should be enough. If it's soft, fiberglass patch.