Can we ask you many technical questions, before having you do paid work?

No. Sadly, I have had several cases of prospects asking countless technical questions, but never resulting in any work. One prospective project manager asked me many rounds of questions, all of which I answered, and all of which required substantial research. But he never sent any work my way. Months later, he was back on the same Web developer mailing list, asking the same types of questions — seeking another victim for unpaid research.