First off, a written contract is not required for your initial agreement to be valid. Do not sign the written contract unless it has only the same terms you agreed to in the verbal agreement.
Basically, you must complete your original verbal agreement, or his lawyer father may come after you for breach of contract. You do not have to enter into any other contracts. If he (or his dad) don't like this, ask them if they will cancel the contract, in which case you're off the hook completely.
If you want to be a part of this venture beyond your original agreement ($400 for the contract work), come back with your own proposal (ideally, a co-founder size equity stake).
It makes sense for you to get a co founder position, since it appears that you are the only one who can create the site, plus they will need someone to keep up the site and implement changes as they need them.
The downside is that from what I can see this person might not be the best choice for a co founder. Especially if he undervalues the need for a technical co founder on a "web 2.0ish" startup. The upside is that you do have access to an inexpensive lawyer.
Basically, you must complete your original verbal agreement, or his lawyer father may come after you for breach of contract. You do not have to enter into any other contracts. If he (or his dad) don't like this, ask them if they will cancel the contract, in which case you're off the hook completely.
If you want to be a part of this venture beyond your original agreement ($400 for the contract work), come back with your own proposal (ideally, a co-founder size equity stake).
It makes sense for you to get a co founder position, since it appears that you are the only one who can create the site, plus they will need someone to keep up the site and implement changes as they need them.
The downside is that from what I can see this person might not be the best choice for a co founder. Especially if he undervalues the need for a technical co founder on a "web 2.0ish" startup. The upside is that you do have access to an inexpensive lawyer.