excuse me ,well i m afraid that yo are guiding them wrong actually what i have experienced is that every device has an chip and controller that cannot be used by us and that contains the assembly or probably machine level program like we have in our computers which we call bios ,so its clear that we cannot flash bios on our-self a special software provided by motherboard company can only update it similarly our devices too have an chip and controller that can control hardware keys and usb connection and thats proved ,i actually experimented to install the lg kernel and got installed and my device didn't booted up the andro os but recovery and fastboot and mmx logo worked fine,so making it clear kernel doesn't damages the internal firmware which control the keys and usb
u can try yourself just clear boot at recovery even then ur device will boot normally except it will not boot android os untill and unless u flash a kernel ie boot.img because kernel is like drivers for windows 98 without installing which you cannot even use a keyboard
i request u to plz do some research before commenting something about technology becoz an unjustified fear can be a roadblock in development