I had the same plane. Put it through hell. It could really take a beating (surprisingly). I was actually training my girlfriend on mine. It's such an easy flyer that she picked it right up. In fact, I have no problem what so ever about recommending it as a first plane. This plane is proof positive you don't have to go with a high wing for a trainer. It has all the good characteristics a trainer should.

About your engine mod, I did the same thing. Flipped my OS 46LA right side up and left off the cowl. Worked great! You could cut a hole in the top of the cowl if you want to. I see no problem with that. Look a little nicer I guess.

The only complaint I have about that plane (and this is true of many others) is that cheesy pvc covering they use on it. It sux and you will have to recover your plane before too long. It won't shrink back with a heat gun. It just bites.