Hi
Good that it is quadratic so you use shell281 and solid186 higher order elements.
Does not have to be midsurfaced, especially if it is not possible.
As for shared topology in spaceclaim see (this will shared edges or faces and create a connected mesh between parts):
For multi-body part in design modeler search that on the internet (there are videos).
If it was me I would move this connection away from the area of interest.
All the best
Erik