A few thoughts from my experience:
I always adjusted the wheel bearings up so that I had zero play, but just
ran freely. Sometimes I used shims so I could get a setting between the turns of the castellated nut. Good grease and Timken bearings (Chris Witor).
I tried to get as close to zero run out on the discs. Thoroughly cleaned both surfaces and used small pieces of wet paper between disc and hub for the final adjustment. Only wet so they stick while disc is refitted.
Tyres would need a cleaned up with a wire brush to remove rubber they had picked up from the track and the fronts would need rebalancing often.
I would do the above after every second race meeting, or sooner if any issues arose.
I also found that the poly bushes on the front drag struts (mine are adjustable) would wear /tear themselves to bits unbelievably quickly so I had some very hard / tough ones made. They have lasted well and tightened up the front end.
Could the wheels be ok at speed but still give issues under braking ?
Yes, absolutely. Braking on the track is always full on and changes the dynamics significantly. Any deficiency will be magnified hugely.
There's an example of steering judder in my car in this video https://www.youtube.com/watch?v=6-iVG8Gtgo4