All reports from lamania indicate you can not apply dual shard effects to the rings (Min II, Lit II, etc), further separating the gulf between weapon melee and handwraps. In fact, you can't get even the special single shard crafting on to the rings (greater disruption for tri-positive, example). Using recipe for blast effects appears to give you the equivalent bursting (elemental burst, holy burst) to unarmed dmg BUT does not stack with the handwraps themselves (holy/burst handwraps + holy burst on ring still equals a single holy burst proc'ing per hit).
Problem to get the halfling dragonmarks you need 3 feats. The only one I see you could possibly drop is IC: Blunt and get another feat at 18. Still needs one more feat to get the third (and best) dragonmark, possibly dropping CE, using the 4 build points to bump dex to 18. All level ups in dex + halfling dex enhancements should give it respectable AC w/o it, allowing the constant use of PA to dish out more hurt.