High def and Mdef should work.
No it wouldn't , MDEF doesn't reduce the damage from the int part of SB.
As for Def , I am sure dagger types also use IP/Cks apart from TSS glads.
In case of Querubin , she plays unconventionally - she has a lot of funny weapons that she swaps.
The fun part is that shes successful with them too.
People who play unconventional and different from cookie cutter builds and techniques are always on a level of their own.