[T-Mobile, Samsung Galaxy SIII] gerald_webb:
UPDATE:

I managed to enable ADB during boot, by using the ADB shell while the device was in recovery mode.

gwebb@mymachine ~ $ adb push ~/.android/adbkey.pub /data/misc/adb/
gwebb@mymachine ~ $ adb shell
~# cd /data/misc/adb/
/data/misc/adb# cat adbkey.pub > adb_keys
/data/misc/adb# cd /
~# mkdir /system2
~# mount -o rw /dev/block/mmcblk0p14 /system2 ## NOTE: for this command, had to figure out which partition was the system partition; here it was /dev/block/mmcblk0p14
~# echo "persist.service.adb.enable=1" >> default.prop
~# echo "persist.service.debuggable=1" >> default.prop
~# echo "persist.sys.usb.config=mtp,adb" >> default.prop
~# echo "persist.service.adb.enable=1" >> /system2/build.prop
~# echo "persist.service.debuggable=1" >> /system2/build.prop
~# echo "persist.sys.usb.config=mtp,adb" >> /system2/build.prop
~# ## now press Ctrl-D to exit the ADB shell

NOTE: thanks to [MENTION=7073896]ErnestChia[/MENTION] for the following post xdaforums.com/showpost.php?p=63829295&postcount=27

So, I was able to get a logcat during the SetupWizard.

There were 3 lines, related to the SystemUI, that were repeated over and over.

W BroadcastQueue: Timeout of broadcast BroadcastRecord{51dfd23 u-1 android.intent.action.TIME_TICK} - receiver=android.os.BinderProxy@448f719, started 10010ms ago
W BroadcastQueue: Receiver during timeout: BroadcastFilter{a4079bf u0 ReceiverList{4b103de 730 com.android.systemui/10018/u0 remote:448f719}}
I ActivityManager: Skipping duplicate ANR: ProcessRecord{768d889 730:com.android.systemui/u0a18} Broadcast of Intent { act=android.intent.action.TIME_TICK flg=0x50000014 (has extras) }

All I've gathered is that SystemUI isn't responding.

Which seems to have started during boot, with the following output.

W ActivityManager: Timeout executing service: ServiceRecord{dd2251a u0 com.android.systemui/.ImageWallpaper}
E ActivityManager: ANR in com.android.systemui
E ActivityManager: Reason: executing service com.android.systemui/.ImageWallpaper
E ActivityManager: 4.1% 730/com.android.systemui: 2.2% user + 1.8% kernel / faults: 1246 minor 2 major

SystemUI Stack Trace

Cmd line: com.android.systemui
Build fingerprint: 'samsung/d2tmo/d2tmo:4.3/JSS15J/T999UVUEMJC:user/release-keys'
ABI: 'arm'
Build type: optimized
Zygote loaded classes=3986 post zygote classes=991
Intern table: 46441 strong; 62 weak
JNI: CheckJNI is off; globals=427 (plus 368 weak)
Libraries: /system/lib/libandroid.so /system/lib/libcompiler_rt.so /system/lib/libjavacrypto.so /system/lib/libjnigraphics.so /system/lib/libmedia_jni.so /system/lib/libsoundpool.so /system/lib/libwebviewchromium_loader.so libjavacore.so (8)
Heap: 5% free, 12MB/13MB; 84371 objects
Dumping cumulative Gc timings
Total number of allocations 84371
Total bytes allocated 12MB
Total bytes freed 0B
Free memory 813KB
Free memory until GC 813KB
Free memory until OOME 179MB
Total memory 13MB
Max memory 192MB
Zygote space size 1972KB
Total mutator paused time: 0
Total time waiting for GC to complete: 0
Total GC count: 0
Total GC time: 0
Total blocking GC count: 0
Total blocking GC time: 0
...
"main" prio=5 tid=1 Native
| group="main" sCount=1 dsCount=0 obj=0x745992a0 self=0xb77f9b30
| sysTid=730 nice=0 cgrp=default sched=0/0 handle=0xb6efab44
| state=S schedstat=( 0 0 0 ) utm=64 stm=14 core=1 HZ=100
| stack=0xbe5d0000-0xbe5d2000 stackSize=8MB
| held mutexes=
native: #00 pc 0004290c /system/lib/libc.so (__ioctl+8)
native: #01 pc 00049391 /system/lib/libc.so (ioctl+14)
native: #02 pc 0001e8c9 /system/lib/libbinder.so (android::IPCThreadState::talkWithDriver(bool)+132)
native: #03 pc 0001eefb /system/lib/libbinder.so (android::IPCThreadState::waitForResponse(android::Parcel*, int*)+38)
native: #04 pc 0001f0b1 /system/lib/libbinder.so (android::IPCThreadState::transact(int, unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+124)
native: #05 pc 0001a0b3 /system/lib/libbinder.so (android::BpBinder::transact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+30)
native: #06 pc 00089471 /system/lib/libandroid_runtime.so (???)
native: #07 pc 00db9189 /data/dalvik-cache/arm/system@framework@boot.oat (Java_android_os_BinderProxy_transactNative__ILandroid_os_Parcel_2Landroid_os_Parcel_2I+140)
at android.os.BinderProxy.transactNative(Native method)
at android.os.BinderProxy.transact(Binder.java:503)
at android.hardware.ICameraService$Stub$Proxy.getCameraCharacteristics(ICameraService.java:421)
at java.lang.reflect.Method.invoke!(Native method)
at android.hardware.camera2.utils.Decorator.invoke(Decorator.java:80)
at java.lang.reflect.Proxy.invoke(Proxy.java:393)
at android.hardware.ICameraService.getCameraCharacteristics(ICameraService.java:-2)
at android.hardware.camera2.CameraManager.getOrCreateDeviceIdListLocked(CameraManager.java:635)
at android.hardware.camera2.CameraManager.getCameraIdList(CameraManager.java:99)
- locked <0x0da89d30> (a java.lang.Object)
at com.android.systemui.statusbar.policy.FlashlightController.getCameraId(FlashlightController.java:126)
at com.android.systemui.statusbar.policy.FlashlightController.<init>(FlashlightController.java:62)
at com.android.systemui.statusbar.phone.PhoneStatusBar.makeStatusBarView(PhoneStatusBar.java:1087)
at com.android.systemui.statusbar.phone.PhoneStatusBar.addStatusBarWindow(PhoneStatusBar.java:3285)
at com.android.systemui.statusbar.phone.PhoneStatusBar.createAndAddWindows(PhoneStatusBar.java:3281)
at com.android.systemui.statusbar.BaseStatusBar.start(BaseStatusBar.java:619)
at com.android.systemui.statusbar.phone.PhoneStatusBar.start(PhoneStatusBar.java:800)
at com.android.systemui.statusbar.SystemBars.createStatusBarFromConfig(SystemBars.java:106)
at com.android.systemui.statusbar.SystemBars.onNoService(SystemBars.java:58)
at com.android.systemui.statusbar.ServiceMonitor.startService(ServiceMonitor.java:230)
at com.android.systemui.statusbar.ServiceMonitor.-wrap5(ServiceMonitor.java:-1)
at com.android.systemui.statusbar.ServiceMonitor$1.handleMessage(ServiceMonitor.java:73)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5466)
at java.lang.reflect.Method.invoke!(Native method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)