As far as the battery issue goes, try the reconditioning method detailed elsewhere in the forum but in a nutshell, it involves letting your phone's batter fully discharge two or three times and then fully charging it. I have tried this just for the hell of it but only out of boredom as I have no noticeable battery issues to begin with. It may help you though; if not, indeed, just get a new battery. Not all batteries are made alike.
As for the freezing, like the others said, it could be an app you have installed. People say Task Killers are sometimes the culprit, so you may experiment with that. I've been using TasKiller since about the first night I had my Droid and haven't had any problems.
You might trying going into Settings>Applications>Manage Applications then press the menu key and press Filter and choose All. From here, go into all your applications, noting and becoming familiar with which ones have "Cached" information. Clear any cached information. If that didn't clear your browsing history and whatnot, go into the Browser options and do that as well, then restart the phone if you want.
If you don't have a Task Killer application, that might be your problem as well. I'm no Google or Motorola engineer but common sense tells me they wouldn't have released phones that were incapable of functioning properly without Task Killing applications, else they'd have included them. Nonetheless, you may notice a minor performance improvement with a good one; I recommend "TasKiller free." It'll allow you to kill some running apps in the background that you may not need or be using at the moment.
If nothing works for you I'd obviously suggest taking it to the store to see if it is a manufacturer defect, in which case you would get a replacement.