regular road shoes are fine for that kinda thing... race shoes are only going to knock of a few seconds a mile, which is neither here nor there until you're at the front of the field - though it didn't stop me forking out for a pair
I wouldn't have thought the not going out for a 'good run' (by which I assume you mean partially hard/fast) will have hindered your performance as you should be tapering to some extent anyway. The people pulling away from you at the end is probably a case of setting off a little too fast (or possibly everyone else setting off too slow). I know I tend to set off quite slow and catch people as the race goes on - it seems very rare that I get overtaken, though this probably indicates I could afford to start a little faster.