I recently bought a Sea-Pro 22CC with a Yamaha 4-Stroke 225

Im wondering what the maximum operating range for this engine would be?
The manual I got says the Max RPM is 5000~6000 but that isnt really
that specific. Im thinking the max RPM is WOT RPM?
Does anyone know if this is a downscaled 250 and if it is a strong
engine that could mabe stand the stress of periodic bursts of speed?

Ive bin running my boat out lately and at 3200 rpm its only getting 22
mph (with three people and almost 90 gallons of gas). Im thinking such
a small boat with quite a over sized engine as the manufacuter suggests
a 150-200 engine that the boat would be capable of higher speeds
without damaging the engine?

Also im wondering if the trim is having an adverse effect on the
engine, I usualy tilt it all the way down to get plaining so i can see
infront of me and tilt it up a bit after to get a better speed but it
only changes about 1mph. Im fairly new to outboard engines and larger
boating in general so any help or advice is greatly appriciated.

Thanks