Nope, not the same. Unlocked simply means that your phone can operate with any compatible SIM card for any compatible network/carrier and not is not, well, locked, to a specific carrier SIM.
You can still 'freeze' some apps even if you're not rooted, but if you want to remove bloatware, then yeah, you'd need to root your phone to do so. Just remember, make sure you do a little research and find out which bloatware apps are actually safe to delete and which ones are not. You might not cripple your phone, but you might affect your service if you delete something the carrier requires.
As for freezing apps, just go to the Application Manager, 'ALL' tab, and from there, tap on each application. If you can turn it off, then it can be frozen. If not, it means it's a system app or a carrier-enforced app (note that you can have non-essential system or carrier apps, though. For instance, some Samsung tablets list the annoying and mostly useless NYTimes app as as a system app, and thus, cannot be uninstalled, but it can be turned off).