RP8 - get a training Captain to explain to you why the pitch rate slows during rotation - it is pretty 'normal' with low mounted tailplanes - I guess your 'past' had 'T-tails'?
You have not specified the V1/VR gap (and I assume also you mean 500mRVR?). Like The Chitterne I think 'delaying' rotate is fraught with danger, not just runway remaining but obstacle clearance - think of where you are placed perf-wise if second engine goes due to debris damage? Will you make the screen height? I would run that idea past your trainers if I were you!