Hi,
The values are not shown with the 4.8 toolchain due to a known issue with the toolchain. The gcc and gdb versions of the Android NDK 4.8 toolchain are too far apart and default to different debug symbol versions. Please add -gdwarf-3 to LOCAL_C_FLAGS in Android.mk. This flag forces gcc to produce debug info in an older format compatible with the older gdb and should fix the issue. Please rebuild your project with this flag before trying debugging again with the 4.8 toolchain.
As for the breakpoints not being hit with clang 3.3, we would need to see the full gdb log to diagnose that issue. Please enable gdb logging on the GDB settings page in VisualGDB Project Properties. Then start debugging, replicate you scenario (make sure some breakpoints were set), stop debugging and give us the log from your project directory.
Please note, that if you are debugging code that is executed very early in the app startup, then try enabling the Android->Debug Options->Debug App Startup option.