Yes. This Magpul Industries MOE SL Mid-Length AR-15/M4 M-LOK Handguard will fit your rifle, and any AR15 rifle that uses a mid-length gas system with a delta ring and handguard cap.
This Magpul Industries MOE SL Mid-Length AR-15/M4 M-LOK Handguard is for Mid-Length gas systems. The model at the link below will work with Carbine Length gas systems. The Magpul Industries MOE SL Carbine Length AR-15/M4 M-LOK Handguard is compatible with AR15's using a Delta Ring, round front handguard caps and an A2 Front Sight Gas Block. If your rifle meets those requirements the Magpul Industries MOE SL Carbine Length AR-15/M4 M-LOK Handguard will work.
https://www.opticsplanet.com/magpul-ar15-carbine-moe-slim-handguard-stock.html
Yes, they should be compatible.
It will only work if your M&P Sport II uses a mid-length gas system. Most M&P Sport II use a carbine length gas system, so if your M&P has a carbine gas system you will want the following: https://www.opticsplanet.com/magpul-ar15-carbine-moe-slim-handguard-stock.html
That would be completely dependent on what exact model of DPMS you have. This handguard is meant specifically for an AR-15 upper receiver that uses a mid-length gas system, so you will need to verify the specifications of your DPMS and confirm whether it is an AR-15 model with a mid-length gas system.
Yes this will work according to Magpul website.
Yes, the factory sling swivel must be removed from the A2 front sight assembly for installation.
This handguard is a mid-length handguard. It is meant to install on AR's with a gas system length that is approximately 9 inches long. A carbine length gas system is right around 7 inches from the upper receiver to the gas block and mid-length is the next length at 9 inches from the upper receiver to the gas block.
It will only work if your M&P Sport II uses a mid-length gas system. Most M&P Sport II use a carbine length gas system, so if your M&P has a carbine gas system you will want the following: https://www.opticsplanet.com/magpul-ar15-carbine-moe-slim-handguard-stock.html
No, that would not work, it requires a mid-length gas system and A2 front sight.