Hehe :smiling3: Yes, there was a turret crew — TBH, 1940s technology wouldn’t have been up to creating an unmanned turret for this type of thing. The photos of the prototype show hatch openings (without hatches) in the roof:
I don’t have my copy of Hunnicutt’s Sherman at hand, but I think it mentions the turret crew too.
As for infantry support: any anti-aircraft gun makes a good infantry support weapon :smiling3: The Americans tended to use theirs mainly in that role in Europe, largely due to the lack of German planes to shoot at. The main problem is usually that they’re too lightly armoured to withstand much return fire, though.