ForScience6686

Yes they are difficult.  You usually end up with offset center off thrust and mass.  As well as, if you do have wings, offset control surfaces.  Altogether making it difficult to control on the way up.  A good design won't need much input from the pilot to avoid all the control over correction.  But not having wings defeats the purpose of the shuttle which was designed for a gliding reentry and landing.  So you may struggle to bring yours back down from orbit.  Anything can be done, you'll just have to engineer your way through the obstacles.

Cycle through the views with the v button, use locked to orient the camera in the proper direction.  That should solve your issue.

You could fly up the modules placing the core in the booster stage, allowing you to return the booster to kerbin.  Then use a tug to attach the modules together.  I have used this technique myself to reduce the parts on each module, as well as get some return on the booster stage.

28 total.

At minimum, add a vertical stabilizer at the rear for yaw control.  I would also give the wings some incidence to improve lift and pull col closer to com.