I know this is probably a stupid question, but is it ok to use a baitcasting rod with a spinning reel? Thanks in advance.

I wouldn't.......

The 1st or stripper guide (usually a short double foot #10mm or 12mm guide) will cramp the way the line comes off of the reel (will probably ball up in front of the guide).

Your line is coming off the spool in large curls, and, the large size 20mm stripper guide is tall and tames some of the coil until the coil gets to the (smaller) running guides which help straighten it out in the cast.

Just an old rod builders .02¢

Good Luck & Tight Lines!!!!