I've got a few cracks on the top of my new (taken it out about 5 times) 5'10" EPS groveler

I'm a noob to surfboard damage/repairs, so I'm trying to see if the largest of the cracks (top of first picture) is something that should be repaired professionally, patched up with a little solarez or something, or if it's fine as is. If I run my fingernail along the deck, I can just barely feel the largest of the cracks. The board doesn't move when I press on/around the crack. That larger crack also has some white-ish discoloring under the glass--is this indicative of water getting in, or something else? Compare that to the crack at the bottom of the first image, where there is no discoloration. As far as I can tell, there are no other signs that water might have gotten in (extra weight, water seeping out)
There are 3-4 other, smaller cracks, all of which are along the stringer (second picture). Against my better judgement, I did leave the board out in the sun for an hour or two last time I took it out--melted my wax right off. Could this be a heat-related issue, or some other cause that might result in the foam around the stringer expanding/compressing at a different rate than the stringer itself, cracking the glass?
EDIT: the cracks range from 1"-1.5" (2.5-3.5cm)in length; the pics make them look a bit larger than they are.
Any thoughts/advice you might have are welcome! Thanks!