Noob needs cross class ability question answered please :(

[Umo]

ok for example.
I am on my level 25 THM and I would like to be able to use "raise" "protect" "Aero" and it tells me I cannot use them in my current class when I try to use it?

Can I not use these?

You shoud be able to use them on THM. Have you selected them on Actions & Skills > Additional? I mean, you have to go through said route, select Conjurer icon, select Raise, Protect and Aero (actions will become available on the bottom part of the window) and then drag & drop those actions to your hotbars.
Do not try to drag & drop actions themselves, but the botton ones instead once you have selected them.