I thought there had been some searching for a solution to the "faster than 31, no turning" issue with no results. I'll give this a try to, during my long holiday break.
I have done several personal mods with above-32 speeds, and I, for one, found the "31+ straight only" to be an interesting consequence. You can still interact with anything else in play (fire weapons, drop mines, launch fighters), and FWIW, HETs still work. I've had ships move at 90+, and when coupled with a high acceleration (300+), it can create a different combat dynamic.
One thing to note - AI ships, including any wingmen you have, will not go past 31. Changing the top speed only works on the ship you are flying, and if you switch from one ship moving at 32+ to another, the ship you left will slow to 31.