I've noticed you didn't do a write up for the SCAG options. Booming Blade, Green-Flame Blade, Lighting Lure, and Sword Burst are all intended to be default cantrip options for warlocks (mostly to give Bladelocks a bone, I presume) but you don't have to waste your Tome features in picking them up, if you don't want to.
The Undying patron is some kind of pseudo-healer who can prevent the party from bleeding out or dropping below 0 hps (almost as good as raw healing imo), but lacks access to restoration abilities.