I think you'll have trouble with side-side racking because there are no diagonal supports and drawer slides usually are too loose for FFB wheels. Back in the old days (e.g. around Y2K), I had non-FFB wheels that were attached to a keyboard tray that was on a drawer slide and that was marginal, which is why I think a FFB wheel will be even worse despite the reinforcement and locking screw.
I'm having trouble understanding how the arm's drawer slides won't sustain the pressure of a force feedback wheel being turned, while it's arms is fastened in place by two opposite bolts. If that doesn't work, I'd consider replacing a 1/2" plywood piece with an identical dimension in its place.
I've released a second a version that allows the main arm's angle to the base be adjustable between a 25 & 45 degree angle at 5 degree increments. And as well with a pivoting bracket to improve the rigidity from force feedback stress. I have more confidence this would be sturdier than my computer's desk.
You need to make it a lot stronger. I don't want to sound negative but every joint you have and every place where you have attached two things together you have chosen very flimsy way of doing it. You don't really seem to understand your materials either. You are screwing bolts to the sides of plywood. Plywood does not do well when used like that and will simply tear the layers apart if you try to put screws to the sides of the plywood and then use it as a stressed part. Probably breaks already when screwing it together unless you take precautions.