Please reach out to the manufacturer directly as Wilson does not provide any information on that question.
Yes, it absolutely should.
OAL for this handguard is 10.6". It will work for barrels 11.5" or longer.
No. But we do have older high-profile 10" rails on clearance for his model receiver. https://shopwilsoncombat.com/TRIM-Tactical-Rail-Interface-Modular-AR-10-DPMS-10/productinfo/TR-TRIM-AR-10-D-10/