Unrooting to resolve connectivity issues

Two weeks ago, Sprint had sms issues. Next day they cleared up for my wife, but not for me. Specifically, while she could send and receive sms on her LS990, I could only receive sms on my LS990. Called Sprint and they had me enter the ##72786# into the dialer and power cycle the phone (I think it was the 72786 code). At that point, my phone would not connect to the Sprint LTE network to make calls or access the internet. All apps dependent on an internet connection displayed errors.

Prior to this, I had problems updating the profile and PRL...meaning, I would select each option and nothing would happen. The phone would not display a new screen, no message popped. I concluded that no update happened because the PRL version remained the same.

I rooted long ago using stumpd. I also recall doing something to block the OTA OS update, though don't recall what that was now.

Okay, so the questions:

1) If I do a factory data reset, do you think my sms, internet, and phone connectivity problems will be fixed?
2) If I do a factory data reset, will I brick the phone if I do the reset before unrooting the phone?
3) I've seen a couple of threads about using the lg flashtool to unroot and return to stock and they're intimidating. Do you have any advice or a suggestion on the best resource to unroot the G#?

Thanks in advance. I hope I provided enough information for some help here.