I am renovating basement in the recently purchased house and plan to put FLOR brand carpet tiles onto the existing concrete floor. Interestingly, there are long narrow cuts in the concrete along 2 walls. They are up to 2 inches deep.

I am wondering what's their purpose. The basement seems to be reasonably dry. Would it be safe to cover them with carpet tiles?
Also, a separate question. There are sizable gaps between the baseboards and the floor (visible on the photo). At places they are greater than the tile thickness. I would think to caulk and paint the gaps . Does it make sense? As I understand, they are not there on purpose.
Thanks for any advice!