Man, don't I feel ahead of the game
That one's getting reworked this week.
Your truck looks like it should come out great
The Wheely King axle is IMO a far better choice than the Axial axle. To get Slash/Slayer width I used STRC axle wideners and Slayer wheels on STRC 14mm hex adapters. This might not work out right for you because SC10 wheels are the only option that might
work for you without modifications. Unless you can find a company (Jconcepts?) that makes wheels of the same style for the SC10 and Slayer?
The only constructive criticism I have to offer is on your chassis upper link mounting points, that might hold for a crawler but you'll want some bracing there for a truck which will be doing 30+MPH.