If you are interested in rooting you should actually prefer to use a PC: on any phone that's the cleanest and safest way. But preferences are pretty irrelevant now, since the security holes those "rooting apps" used have been closed in the last few versions of Android, so if it's possible at all with your phone I'm sure it will need a PC.
As for locked bootloaders, if you read the earlier posts you'd know that it's down to the carriers rather than Samsung. I advise you not to waste your effort arguing with Verizon (or Samsung) that it's your phone so should be unlocked: the carrier sold it to your friend with a locked bootloader, and if your friend sold it on to you then that's between you and him/her, and you'll get nowhere with that argument.
If it's bloatware you are concerned about there is a package disabler app for Samsung phones (mentioned 2 posts above yours) that doesn't require root. You can find it here:
https://play.google.com/store/apps/details?id=com.ospolice.packagedisablerpro