wait, you have a freewheel. i'd put the back brake back on till you get a fixed back wheel. it's the less important of the two brakes, but i'm sure you'll want to be able to stop your back wheel now and then.
just a suggestion.
also, i dunno how it is where you live as far as hills, but i used 52/14 in portland and boise for the longest time on a geared bike. i just didn't ever change the gears. the hills in portland were all right. the one on interstate was a beast with that gearing. but boise's not bad like that, though i've since used a lower gear to work on my spin. i'd suggest that to you, but different things work for everyone. on a freewheel bike, though, i'm not completely blown away by that gearing...diff'rent strokes.