7th Ed. Quicky about the EOTG

The engine makes the priest riding it an extra wizard level. If I upgrade him to a lvl 2 wizard, will he then become equal to a lvl 3 one?

 

Yep.

 

Nice, then my evil schemes are correctly composed..

 

Only for power and dispell dice, you still do not get an extra spell.

 

And he also gets to cast spells with one more die. He's like a lv. 3 wizard in all aspects, except that he still only has 2 spells.

 

It's just as it's written in the book. No questionable formulation.

 

Of course you can always give him the Plaque of Tepok to make him a Level 3 wizard in all aspects, lol.

 

so at the start of the battle, does he roll 2 d6 or 3 d6 for spell selection??

 

2d6, since he has 2 spells. Unless you take the plaque giving an extra spell, then you get 3d6.