Thanks, SalvaG .
I forgot anonym proxies, sigh!
My first task will be to find a way to be able to recover from bricking. Having linux and flash main storage system I'm quite sure it has a variant of RedBoot flash boot code and main boot flash system. Normally those boards have a pre-boot stored in a serial FPGA that loads arm code and then that code searches for a boot file in flash, and if that file exists, boot code flashes the entire system and if it does not exists it jumps to normal boot in flash. This way nobody will brick it anymore.
IMHO main problem here is to find what keyboard combination forces the entire system flash writting. AFAIK those serial FPGA are umbreakable and I haven't a JTAG for that system...
PS: I think I will got the fourth option: record bricking in 0 days after reception. :-P
PSS: ¡Quiero mi Kindle yaaaaaaaaaaaaaaaaaaaaaaaaaa!