One of the more interesting aspects of being a project manager consultant for a large law firm was learning the pros / cons of contracts.

Pros? Clarity

Cons? Enforcement

Unless one has significant financial means to enforce the contract - as you mentioned in this post - there's no point in said contract.

Over the years I've learn the hard way to keep it simple. Simple =

1) a non-refundable retainer to include detailed deliverables, time frames, penalties.

2) a specific time frame with a hard end date.

3) rinse and repeat.

My clients were always referred to me by other clients. Future clients knew they'd be on a waiting list because existing clients knew I never over-extended as well as managed scope-creep with an eagle-eye.