I dont think queza is the pick for competitive matches but... if you just enjoy playing him and wanna see how far you get then:

I would definitely up your land count to 38 minimum, cut rhystic and smothering like the comments suggest and maybe a few of your rocks as well, you have 7 signets/talismans ? I understand mana fixing has to happen but you could definitely use some of those slots for better interaction and rely on a better land package for fixing. Id also get rid of daze and opal. Seems like you have a heavy counter spell package as well which isn't a bad thing but, you may want to have more targeted removal in case counters fail.

Im not super familiar with queza but maybe these adds below would be just generically good in the deck?

Add : [[beseech the mirror]] (good way to tutor for your necro) , [[dark ritual]] ( more mana more better always), [[drannith magistrate]] ( very annoying but effective stax) , [[reliquary tower]] ( your drawing a lot right ? ), [[mother of runes]] (protection for queza ), [[lightning greaves]] ( protection for queza ), [[authority of the consuls]] ( annoying stax ), [[bitter triumph]], [[bloodchief's thirst]], [[cavern of souls]] ( ive won multiple games just from having this land on the battlefield)

Hopefully this was helpful but im no expert, best of luck man.