Re Incentives: we are looking at a number of options and would be interested to hear from you if you would like to be included. The Beta Test Program is being managed by Frog's UK Product Manager (Karl Bolland) so I would happily put you in contact with him to discuss this in more detail. PM me your details and I will pass them on.
Also, in relation to basic functionality - Karl is also looking at various areas of the product based on feedback from customers with a view to developing the core product. Again, PM me your details so I can pass this onto him so he has someone to go back to.
In relation to patches being released with new bugs - the additional improvements made to the bug fix and release process will reduce this and getting schools involved will also assist further. It's not possible to guarantee 100% bug-free software, but I do understand your frustration.
Regards
Mark