Deferred payment model, an industry standard for legal services for startups, implies that you do not pay us anything at the start. Your first liquidity event, e.g. Seed round, will trigger the payment to us in a combination of cash and equity, at that point in time.
No, we would work to sell back the shares to you after Series A.
We are willing to take risk on you. If you don't end up making / raising money, then we get nothing for all our time and efforts. But that's fine.