For Wizard, what spells should I adjust for more control? I think I need walls and bigger damage options? Is there a way to get an 8-9 dice attack?
Plenty. With walls, I can't think of any without convoluted methods (like a Jet Stream plus successful push through a wall) - I actually highly rate the Wall of Thorns for damage. Against an unarmed Mage is devastating. In fact, I got a kill when on the ropes using this tactic: quick cast a Jet Stream for 2 dice damage, push was successful and moved him through the Wall of Thorns for a further 10 dice of damage (five lots of 2 dice). And then as my action I repeated it and killed him
And remember, pushing them into the arena walls do 3 dice damage when pushed into them. Oh, and teleport trap/hellfire trap trigger when you push an opponent into them too
As for bolstering damage options, there are attack spells (fire and lightning being the heaviest damage options currently). Add Hawkeye and applicable 'plus damage' ring for two extra dice. As for creatures, many of the Arcane school creatures are worth a go, and pretty dangerous to boot.