If all you did was root and/or install Safestrap, you can uninstall both of them. (Uninstall Safestrap, then remove busybox, then uninstall root.)
If you flashed a different ROM and don't have a backup of your stock ROM, there's a UrDroid thread on XDA that will give you an Odin-installable rooted stock ROM (use the Odexed one, in case they actually check.) Install it and unroot it.
Unfortunately, with more people bringing their phones to work at large corporations, I think we'rre going to see more manufacturers locking phones down. The percentage of people who care whether the bootloader is locked or not is tiny. It's like orphan drugs - if they're not going to make a large amount of money selling unlocked phones, they're not going to design them.