No idea sorry it's likely a forscan tweak
There are utility files you can run, check the Russian forum.
You don't have enough space on your Apim. So can't update like you are trying to. You can technically replace the 19101 with 19274 and reflash but you could potentially lock yourself out of the reformat tool then.
No idea post your ivsu
1. older APIMS don't change brightness smoothly and therefore having the option to turn off autodim is important.
2. no idea.
I'm english, thats what Google Translate is for ;)
you because you don't have enough storage space to update to 19274 therefore you also wouldn't have enough to go back to 19200 once on 19274 and you can't use the reformat workaround because the reformat tool is blocked in 19274
Master reset
Depends on what languages you need and maps