Agree 3 should be enough and sounds like it drives fine. 1.5 degrees (negative I assume) camber sounds like a track setting... may wear the tires unevenly. If mostly street driven .75 degrees negative may be a better "balance".

If you really want the higher caster, may need adjustable strut rods. I did mostly because of part variation and poly LCA bushings. Cranking them in a bit helps caster... just can't overdo it and bind up the LCA bushings.