[Q] Samsung Galaxy Tab 4 8.0 AT&T SM-T337A Root but NO Recovery topic

Hi Devs,
I've just joined and am uncertain of the proper place for this thread. Apologies if inaccurately posted.

I have the T337A, which I have rooted on ANF4, but I cannot find a recovery. I have read and read but am not finding the solution to my little project. I would like to get a safestrap on this locked bootloader so that I can install and learn to write custom ROMs. I have tried a safestrap but it was not for this specific device and did not work. I have also installed and purchased CWM Recovery and TWRP Recovery, in my learning process. The problem with the recovery is that there is no custom recovery written for this device and the bootloader is locked, as this is the AT&T WiFi/LTE version. So it looks to me like I need to figure out the partitioning image somehow in order to make a safestrap work on this device...as step 1. Is there anything else that I can do with this locked bootloader? I would love to have some help in writing a custom recovery and ROM for this device but I am a tiny tiny noob here and not a hard core programmer. If I could get some feedback on places to start for such a daunting task, it would be great. I guess one thing that I do not understand is why I cannot make my current rooted ROM the default recovery in TWRP. It asks me to choose from the list of supported devices. I understand that it goes: NAND --> aboot.img/bootloader --> recovery/or/kernel --> OS/or/ROM? If this is close to accurate then I would have to write something to the NAND?, which I'm not sure what is yet, in order to hijack the factory bootloader and then write the partitions on the sdCard for the ROM, like the safestrap folks wrote? It looks to me like they also included a version of TWRP touch which I used on the S4 yesterday and was really cool, so I guess that would be needed as well and is also why TWRP does not work for me now...it cannot hijack the locked bootloader. How do I hijack this hard headed thing? fastboot does not work to this device. In the process of this project, I have also run into a roadblock trying to update the /system/framework/framework-res.apk, in the manner that a flash needs to be done, I think. I want to change the /res/values/bools/bools.xml switch "voice_capeable" to true. AT&T or Samsung disable this on this version of the tablet, I guess to sell tethering or something else I'm not familiar with...but the way it looks to me, everything is configured on the device and I have a phone number provisioned for data at least. Why can't I turn on this switch and use the phone portion of the device? Any time I tickle the running framework-res.apk, it kills the OS. I tried compiling an update.zip aligned and signed with test keys or something like that but when I flash it, it fails with wrong footer and invalid signature...then it wipes me back to the stone ages. I warned I was a noob..! ...but not scared to brick some shtuff in order to learn this and write some custom solutions. An after thought...is there a solution for a bootable extSdCard for Android? This might lead to some options if it is possible.

Gathering phone info...
Collecting information. Be patient! Do NOT disconnect the phone!
Model: SM-T337A
Android Version: 4.4.2
Sales Code: ATT
PDA Version: T337AUCU1ANF4
Phone Version: T337AUCU1ANF4
CSC Version: T337AATT1ANF4
Product Code: SM-T337AZWAATT
HIDSw Version: T337AUCU1ANF4/T337AATT1ANF4/T337AUCU1ANF4/T337AUCU1ANF4
Board Platform: MSM8226
Serial Number: R32FA00PMRF
Imei: 3534.............
Unique Number: C1604.......
Connections: AT,MTP,MTP
Battery Status: 4.28V (94%)
Network Type: GSM

SuperSU Pro v2.40
TWRP donate latest
CWM donate v5.5.3.7
BusyBox Stericson donate v1.23.0
Titanium Backup Pro latest
xPosed v2.7.1
Wanam xPosed v3.3.1
NinjaMorph Pro v2.8.2
ROM Toolbox Pro v6.0.6.5
RootLogger Pro v1.9
Nandroid Backup v4.4.5
Next Launcher 3D Shell v3.20
Root Firewall Pro v2.1
SetCPU v3.1.2

w/respect. PitPin