jenbike

Long story short, I should have bought a hybrid bike or other bike better-suited to mostly-street riding, but I bought a MTB. It's a Schwinn Frontier and I got it because it reminded me of the MTB I rode as a teen (when I rode last; I am now 33) and have since learned that I do not need to touch the ground with my feet at a standstill, and that doing so is bad for the knees. I had tested some comfort hybrids but I felt very offbalance and uncomfortable on them.. I have since learned that I probably have to relearn how to ride a bike fully after watching the video about proper starting/stopping; I had no idea about this at all.

If I raised the seat and just went at it, would this MTB be a truly horrible ride for the paved streets, as people are all telling me that it now is? I would really prefer not to return it to the store since any hybrid would be at least $100 more than this was, and I just don't have the money, and if I layaway it, I will be missing out on the whole summer at this financial rate. I am thinking that for now, I can tough it out, and save for some hybrid tires for it. I am not utterly and horribly upset at not getting maximum efficiency at this point; I just want a bike to get on and ride.
I am planning on raising the seat more and making a go of it in a safe carless area tomorrow, to see how that goes. If it is really tough not to wobble a lot, I will see about selling a few things on ebay and just going back to the store with it, but I would prefer not to.