Your phone is almost certainly not permanently bricked. Chances are you can boot into recovery to flash a new ROM. Worst case, you'll have to flash the phone back to stock with RSD Lite.
That said, there's really no way to unroot the phone or flash a stock ROM without having to re-install your apps. You can try flashing a stock ROM without wiping data & cache (or doing a factory reset), but it's probably not going to work very well.
The major apps for restoring 3rd party apps & their data, like Titanium Backup, require root. You can use other avenues to re-install apps (like AppBrain), but you'll have to reconfigure them by hand if you're not rooted. Since you say you're having problems, this might be the safest course of action for a large # of your apps anyway. It's just a bear to lose complex configurations or progress in games.
Since your're already in trouble, the course of action I'd recommend is using RSD Lite to flash the latest SBF availble -- FRG22D in your case. It's available for download from Peter Alfonso's Site. Your phone will update to FRG83 via OTA. Flashing the SBF will wipe all your phone's data. You may even need to reactivate your phone with Verizon, but that's not difficult to do (just dial *228 and press 1). This will not wipe your SD card, so things like backups you have or pictures/videos/downloads on the SD card will be safe. Despite the dire warnings or bricking one's phone, as long as you don't do something foolish like unplug the phone (or pull battery) in the middle of flashing (or have bad luck with a power outage), you should be OK. Using SBF to root and unroot @ DroidForums
If you can still boot into recovery, you can flash the stock ROMs from there and accomplish nearly the same thing -- though I'm not sure it will do things like update baseband. Unroot w/o SBF @ DroidForums
The DroidForums guides are very thorough, and their Rescue Squad group is very helpful.