Absolutely not, just no. Permanent severing is ridiculously prone to abuse, the only way I can see this being reasonable is with express OOC agreement from the person being severed.
Referring to the work as a whole;
Spells such as reflection and absorption seem fine, however warding does already exist. Detecting magic is the most promising spell in this piece, I think with more redlines regarding the circumstances of its usage it could provide some interesting RP. Antimagic is an interesting concept which is relatively unexplored in lotc, but this needs some heavy reworking to be viable imo.