To answer your questions:

1 - An OS 52 four stroke is the ideal engine in my opinion. Mine has the old 61FS (20+ years old) and it's more power than necessary
2 - Build per plan but I recommend 1-2 deg positive incidence in the horizontal tail to reduce balooning
3 - I made the "complex" struts per plan and am extremely happy. Wasn't really difficult to do
4 - No side and No down thrust. It's not required
5 - I simply installed a small, cheap, GWS gyro on the rudder, it takesoff and lands straight as an arrow. Cheating? no, it's called "using technology for your safety and enjoyment".

A lovely model. Did rib stitching and a descent panel on mine, took some time, was worth it.