These all seem pretty solid. I think Testacornibus and Quetz should be tweaked as well to be made relevant. Testa maybe getting a bit more attack/HP and Quetz either getting a bit of its attack back or adding some damage to its counter.
The only one I’d say becomes OP with your changes is Dracocerato. With this buff, it can basically come in and kill longnecks almost cleanly. Especially with decel immunity, it can freely swap in during decel rampage, tank the hit, and proceed to kill/almost kill. Additionally, cleansing shattering impact is in itself pretty overpowered. A 1 turn delay would at least prevent it from wreaking house. Or perhaps giving it cleansing shattering strike.