Are these bikes the same as the R1, that is piston port motor, no reeds.
If so, I did all the things you have done plus the following;
lightened the fly wheel, took of all fins, opened and raised the exhaust ports only about 2mm maximum, had a modified banshee watercooled pipe made up by viper performance, used a 14/14 watercooled carb.
Also fitted a watercooled rear brake set up.
Standard front sprocket was a 17tooth, get rid of it straight away, I was running a 13 tooth.
My bike was much quicker with these mods done.
They are never going to be a real powerhouse though.
I won the championship on it over here in SA.
As with all mods though, do one thing at a time then test it. If you go and do everything at once and somethings not right you dont know which mod has made it worse.
Try these and see how ya go.