General Tile Discussion

Inside of an exterior wall on a raised slab foundation here. Found some spalled concrete in one place that I'd like to fill in before putting floors back in. This room has always had a few spiders and now i know why. The bottom plate of the wall rests on perimeter brick of the raised slab so this isn't a structural issue.

I was thinking of mixing a small amount of self leveler and pouring in here. Any reasons not to use this or would a 2 part epoxy or other product be better? Also, what would be best to fill in the pits left after removing nails from the carpet tack strips? Thanks in advance..... Joe