Ten years is hugely ambitious. I'd suggest that a more realistic option that Wasps would agree to is probably 2 years with an option of a third.
Maintenance would cost far more than management surely depending on your meaning, so I can't see this being agreed to and I think Wasps would probably want us to make a fairly reasonable contribution towards the pitch given that its quality really is far more important for us than it is for them.
Unsure what Wasps would consider as 'fair' for commercial revenue. Again, I just can't see Wasps agreeing to us keeping all the revenue earned from F&B or other commercial income such as parking etc. They didn't last time so why would they now? Also, lets just say for the sake of argument maximum capacity is allowed in stadiums next season (obviously it won't be), do you honestly think Wasps will willingly allow us to take all earned revenue from F&B given our attendances are likely to increase? Whilst games are likely to be played BCD for the foreseeable, Wasps will still inevitably have one eye on this.