I can empathize well. When I was 19 I had no acne and a thick NW1. Even when I progressed to a NW2 at 22 my skin was fine but when I started diffuse pattern loss around 23 my skin also started to increase in oiliness. I get blemishes too, I wouldn't say it's aggressive acne by any means at all but I can't help but think they're related. Part of my truly believes that underlying, chronic inflammation is responsible for hair loss, acne, and heart problems. They all seem to be interconnected in some way.
My 0.02 on finasteride is to hurry and hop on to maintain what you have. If you have that much hair at 30 you will be doing better than almost all of your peers. I have had excellent density recovery recently but no regrowth along the hairline. My side effects were very mild and only lasted about a month. Best of luck, welcome to the warzone.