“I believe the article states that they need the weapons when taking off and landing.”
“If such is being done in Vertical Lift, the props are out of the way.”
Door guns are the best option. A mechanical “stop” could be used to keep them from firing upward into the props and another “stop” could disable the guns when the props are forward in airplane mode.
A belly turret is expensive, you won’t see it for years, it takes up cabin room, it reduces range, it’s less reliable, and I’m not even sure there’s enough clearance between the belly and the ground.
This is true. I think we may end up seeing something more akin to the Apache's chin-mounted 30mm chaingun with a similar helmet/monacle setup to pick out targets from within the aircraft.
You could probably even mount it to the belly without having to clog up the hellhole, but it could make fastroping into a hot LZ even more exciting than it already is. 8^)