MMM Question

I know this maybe a silly question but i have a MMM and i want to run it on a 1/8 electric buggy but use a 1/10 4000kv and above motor on 7.4v lipo.
I know these esc's are ment for higher voltage lower kv motors but are they safe on low voltage high kv setups on 1/10 and 1/8 buggies. Just need to know to be sure.

Also a friend had his MMM case come open leaving the base still attached to the buggy during a race meating on friday and rippeded off the reciever wires
is this covered under warrenty if i send it back to castle.