@VashJohnny Sam Hulick and all of the ME2 DLC composers are back too, so we'll still get that "Mass Effect" feel. From what we've heard so far, I think Mansell's going to be fine.
You forgot to mention that Grunt isn't affected by the shield-draining sunlight on Haestrom (Tali's recruitment mission). He's always a good idea to take on that mission, especially with the Mattock, Claymore, and his Fortification power.
It's a Turian Machine gun called the Phaeston. Leaks confirm it's a new Assault Rifle.