1. Rear- center hole(#2) front- outer most hole (#1) both F/R arms I run the bottom of the shock in the A hole
(outer) I rarely change from this setting but for lower bite conditions I usually move the top of the front shock in one hole(#2) This adds more chassis role and weight transfer.
2. I always run “double” one-ways. Only once did I run my car full time 4wd. That was because the track was super dusty and had no grip.
3. Yes, it especially important to run sway bars with a stiffer chassis. I use black bars F/R. If you need more steering take off the front if you need less steering take off the rear.
If your track has a ton of traction I would stick with your current chassis configuration. But if you’re racing on a loose parking lot track I would give the HB chassis a whirl.
If you want to try just a minor adjustment in flex you could always loosely mount the upper deck with o-rings and washers under the screws… I would probably try this first