Don’t completely get what you want to do. If it’s consistently needing 2 layers you could go for multiple render targets. If you need N layers with different parameters, then you probably want to integrate the glow effect in to your line shader instead of vice versa. Also dx11 texture array renderer might be something could use in this case.
Mmm BSOD generally means you have driver bug, so not much to do with dx11 implementation (your graphics card normally recovers otherwise).
Stability wise it’s pretty solid (couple issues with windows 8 but that’s getting sorted), used it for production on several projects and it doesn’t complain. For most decent applications it normally works smoother.
It’s pretty different and you have much more possibilities, so of course there’s some learning curve, but once you’re used to it it’s generally easier in 11 than 9.