1. Phone is SIM locked to AT&T.
FIX: user @jamezr used http://www.cellunlocker.net/ for $25 and was able to obtain a working unlock code.
Also I requested an unlock code from http://www.swiftunlocks.com. They only charge $9.99. Code was delivered in 2 days (no weekends) and worked without issue.
2. Carrier branding on back of device-
FIX: from user @Affliction716 "On another note the AT&T Deathstar on the back scrapes off without leaving a mark at all!!! Just take a knife or the edge of a credit card and lightly scrape over it. Disappears like it was never there"
3. Bloatware is installed when device is activated with AT&T sim. Can be easily removed.
FIX: Setup the phone without AT&T Sim and it will not show up.
4. On bootup there is an annoying AT&T splash screen. This cannot be removed by simply flashing the factory image.
FIX: From @bodosom Using your favorite File Manager with root permissions:
1: Open /oem/media
2: Mount r/w.
3: Remove or rename the file bootanimation.zip
5. Annoying AT&T default ringtones by default
FIX: Courtesy of @Plexicle (takes care of boot splash as well)
Contents of OEM:
oem.prop contains one line:
The entire oem partition looks completely useless and should be safe to nuke.
I emptied the oem partition entirely. Going to do a quick round of testing and make sure nothing is messed up and report back.
Everything is working great. The only thing I noticed is that the call ringtone was initially set to "Unknown ringtone" after first boot. It was probably set by oem.prop and then couldn't find it after that. Just changed it to a different tone, works great.
From @DA6030: So, it sounds like the single command "fastboot erase oem" should take care of most people, and can replace directions #4 and #5 in the OP. This avoids root or messing with ROMs, for the many users who don't need root, and preserves OTA compatibility from Google. One could even re-lock (fastboot oem lock) immediately afterwards, if one doesn't need the tethering fix.
6. Tethering is disabled unless you have a tethering plan.