There are several paid root apps, but you may never want or need them. Most tools are available for free. It really does depend on how you use your device; rooting and ROMing open up new ways to use it and certain apps will simplify those tasks for a small price. For me, a paid VPN client meets my needs better than the freely available apps--they only work if using a good custom ROM with the kernel modules installed.
Backups are important, but you really don't need Titanium Backup for most things. Clean installs of ROMs and apps are much more reliable; apps can also be copied to an SD card manually before wiping.
If you root, install the custom recovery and do a nandroid backup. Always do a nandroid backup before removing any system app; you may bork it more than you expected.
Although it is a popular root app, I strongly discourage the use of ROM Manager. You do not need it and can save $5 and the potential for some large headaches by avoiding that one. Consider donating to the developer of a ROM or app that you really like; they will appreciate it.