> None of this is well-specified. I'm not saying doing this would be trivial (and you'll definitely want to engage lawyers to help do it), but if you do take s

> None of this is well-specified. I'm not saying doing this would be trivial (and you'll definitely want to engage lawyers to help do it), but if you do take support contracts it will have to be well-specified in the terms of the contract. So the answer to all those questions is that it'll be whatever you and the contracting party want them to be as part of negotiating the contract. The more they ask in terms of speed, guarantees, availability, they more you'll make them pay for the support. If there are things you don't want to do, make the price so high nobody will pay it (or if they do, then hire out the work since they paid you so much for it).