You really can't brick it very easily that's the beauty of Android and Recovery mode If you nandroided then a swift restore is easy or you can simply reflash back to an older rom just make sure to keep multiple roms on the SD card root
As for the latest cyanogen, bam0 have you noticed any bugs? I WANT to flash but I keep seeing people say 4.2 stable is coming argh!
I haven't noticed anything major, the only problem I've had is that MMS broke for me under 4.0.4, couldn't send, receive, or even get notification I'd been sent one, haven't tried it under 4.1.11.1 yet. The speed difference is very, very much worth it.