Like many others, I loved and still love my first cheap bike. Old long heavy touring frame, a little too big, but like my first kiss, I'll never forget it will always love it.

BUT concerning the gear ratio change. Don't do it. If you are riding platform pedals, then its going to be harder to stop. once you get straps or go clip-less, you'll find it much easier to stop. Not to mention, then you can learn to skid/skip. I think that going to 19t will cause you to spin too much and its best to avoid taking cogs and lockrings on and off so much, especially if you have cheaper hubs prone to getting their threads stripped.

I say buy some straps and have fun.