Was Bleriot the real designer of the planes that bear his name or more a businessman and test pilot
I think Bleriot is pretty much as explained in the rest of your post.
He went on to get involved in S.P.A.D., who's fighter aircraft were subsequently used by the Americans (understandably) post their entry into WW1 in 1917.
Hispano-Suiza engines , which powered the S.P.A.D.s ( among others ) were also manufactured under licence in the States by Wright-Martin.
Wright: "having failed to keep abreast of aeroplane and engine technology ( producing) their last engine in 1915"
Bill Gunston's words not mine.
(Aero Engines- Patrick Stephens Ltd.)