So, I've been pouring over forum posts here and elsewhere discovering that this MMS sending/receiving issue I've been having is not "just me" and seems to be an android/google issue with no future fix until at the earliest Sept. I was all set to go to my local store and trade it in for a different phone. The service guy there just happened to have the LG G2 as his own personal phone and was confused about this "issue" I was having. He said he's had this phone since earlier in the year and never had an issue. Even since the Kit-Kat update. The biggest difference between how he uses his phone and how I was using mine is that he's always used Hangouts instead of the stock messaging app. Since I read on here that a few others have had success with Hangouts...I figured I'd do a factory reset and start with Hangouts and see if that doesn't work. Just thought I'd suggest this to others to try as a solution. We'll see if it doesn't revert to messing up again in a couple days.