Thank you guies for your help, I finally took Thai airasia after having required some info on the safey of the different thai airlines on the website JACDEC.
I am not sure that this website gives serious safety analysis, but it seems to be one of the only enterprise providing such service for world travellers.
That is probably a pity, since such kind of enterprise would be very helpful to choose airlines for domestic trips in countries far from our own native country (so that we usually do not know anything about the different airlines in such countries)!
In any case thank you again for your advice and help and good luck!