Midships Thrust - Why not?

With a well you should have it long enough so you can tilt the engine out of the water when not in use to lesson corrosion and barnicle problems, and when in use to untangle ropes and stuff from the prop. With an enclosed well you need ventilation for fumes but also enough fresh air supply so the engine runs right. It won't run good with not enough air or air full of exhaust fumes. Maybe even fan driven ventilation.

As to steering I would think steering by turning the engine alone, it might not steer at all depending on if the fore and aft underwater resistance was balanced. When an outboard is on the stern you turn it right to go left. When it is mounted in the front, you turn it left to go left. There is a pivot point in there somewhere. If you have the engine at the pivot point, it seems you might have a problem.

The rudder will have to be big since you would have no direct prop wash over it to help it turn the hull.

If you do end up with poor performance, making the beer cooler really large might compensate.

 

When the boat passes over a wave, the level of the water in the well will rise and fall with it.

Maybe design the area of the hull around the motor as a flat pannel. Then you could make a cylinder shaped well and mount the outboard into a second smaller cylinder that seals around the shaft of the outboard. This would give you the advantage of 360 degree trust.

Poorly described, but perhaps you get the idea.

 

If a sail drive won't provide the power, why not do what Norwalk island Sharpies, Bolger and a few others - stick a well at the stern so that the outboard is secure, hidden and can actually work like it was designed to - including wash against the rudder,security, positive steering effect etc etc.
This is a proven, viable elegant way to preserve a traditional vessel appearance, and avoids many of the problems associated with centre wells.