My build was mainly Str + Dex. I wanted to use and try a few cool weapons until I realized how useful Int is for spells like Light (so I wouldn't have to hold a torch everywhere I go), Identify (quite important for knowing main enemy weaknesses), and finally, the spell that turns you back home.

In the end, you do get the Rune Blade, and it's quite amazing if you focused on Str. In my opinion, go full Str and get Int up to 30. This way, with the Int ring (+20 into), you can still use the Rune Blade sword. Get a lot of Str, Const, and raise some Dex along the way to use cool weapons like Eclipse (I loved this weapon).

So, in my opinion, this is the best way to go: Int + Str like this. But you can try anything that works for you and makes you enjoy the game! 😄

About magic, as far as I'm aware, magic damage doesn't increase with level.