Did mother talzin use maul?

Did she only use him for her own gain or did she actually care about him

Considering she sacrificed herself to save him... I'd say she cared about him quite a bit.

Yeah, plus she weakened herself to revive him.

And part of the reason she wanted revenge on Sidious was because he took Maul from her.

That said, I'm sure she did use him to an extent. She certainly used the heck out of Ventress and Savage for her own ends.