1. Polishing IS changing the surface; polish does increase the grit number level of the surface. It is not a coating like varnish or lacquer or polyurethane or paint.

As long as you are not speed dominant:
2. In theory, taking the surface to 4000 grit dull/matte will handle the same amount of oil as 1500/2000 grit + polish, as long as you don't get carried away with putting a super high gloss on the ball with the polish. Polish over 1500/2000 grit, will, in general, take the ball to about 4500 grit (depending on the human factors, it will range from 4400 - 5500 grit).

4000 grit dull vs. 2000+polish will be slightly sooner, slightly more even reacting and handle slightly more carrydown.

If you are speed dominant, the change from 2000 to 4000 grit may not be very significant, compared to if you are rev dominant or matched speed & revs. If you are speed dominant, just got to the polish.

I have experimented with several pieces for myself and teammates.
1000 + polish is a very similar motion/reaction to 3000 dull, but alot less ball maintenance
the 3000 dull ball we used had absorbed plenty of oil after 30 games.
De-oiled it, went to the 1000 + polish and had a very close motion.
Just cleaned it every night when done and it definitely lasted longer than the dull ball before we had to adjust the surface again.

to answer your question, absolutely try polish, the ball won't hook less, it will just have motion in a different part of the lane (it should anyways)