I agree with the comments about the wheel-benders - use Sheffield stands or lots of railings instead!
Position is going to be absolutely crucial. I probably can't offer any suggestions that you haven't already considered, but it may be worth asking the Notts CTC for ideas - try looking for gaps in their
café map!
Two establishments which are not particularly bike oriented but seem to attract quite a bit of trade, and might be worth a visit to see what works:
From a couple of slow rides with the local CTC C group, it seems the Kingfisher Lodge at
Portland fishing lakes is even more popular with cyclists than the intended target of anglers. Quite a few cyclists seem to visit it independently of the CTC rides, and probably keep it viable.
Also in the Vale of Belvoir, Dove
Cottage is a cyclist magnet; prices for the delicious cakes are on the high side, but it is for charidee.