Question #1 -
No, not at all.
Remember that detonation can be controled by a proper chamber shape. Rotax has done this. By the use of a small volume, pent roof chamber vs. piston diameter.
Rather than use giant, odd shaped chambers like the old Chevys, Fords and Chryslers (remember that the Rotax engine has a 4.055" diameter bore) and filling them with odd shaped domed pistons to get the compression, Rotax uses a small shallow, cleanly shaped chamber.
Also remember that using an aluminum head, normally a full point in compression can be added vs. an iron head.
AND...the use of a good fuel injector system also has a lot to do with being able to go that high in compression.
The American and most offshore car engines still don't use "port" injectors like the Rotax engine (most bike) does.
All these things add up.
As far as being able to afford an 1190...not me...!
Mike