I've made a spellslinger commander deck with Veyran as the commander and I wanted to get some feedback

What bracket are you aiming for?

General suggestions:

Add way more ramp, fellwar stone, mind stone, wayfarers bauble etc. they'll trigger prowess too.

Figure out if your going for more combo or creature based. I play creature based with a few combos that work well as cards anyway like Storm-kiln artist and Haze of rage combo, and Dualcaster mage Twinflame.

Big score and Unexpected Windfall can be free/mana positive with a few spell cost reduction cards.

Get lots and lots of dice. You need to keep track of so many triggers and it'll annoy your group if you don't have a decent system.