Do I need adjustable cam wheels?

[Grrrrrrr!]

Nope, cam timing of both cams is out by same amount relative to the crank, tensioner just takes up any slack in the cambelt.

Skimming head changes distance from crank pulley to exhaust pulley, changing cam timing by whatever the change in length is.

Distance from exhaust pulley to intake pulley hasn't changed, so timing of those two relative to each other is the same. But since exhaust pulley is out by a tiny amount from crank pulley, the intake timing is out by the same amount relative to the crank.

[pc]

Won't the raise in compression change the ideal timing for the engine away from factory? Therefore the old cam timing wont be ideal anyway.