I’m not well-versed in notation. I hope this is helpful.
1A: menSCH IS Mentally5A: IMPE(R)I(L) assumes initial [r]ent; [l]essens risk6A: missIng letters are vowels1D: (S)KIM[s] 2D: friendsHIP POssibilities3D: S[u]PRE[m]E4D: it’s a good thing = PLUS = too
Thanks, Alex! Glad you enjoyed it. 6A is a pretty straightforward clue. I feel the clue -either as a whole or “missing letters” or even just just “letters”- can serve as the definition, while the presentation of the clue with typos/missing letters provides a kind of wordplay.