So, if I understand your first two points 
correctly, you will never have problem with 
someone from US but only from other country ?

Just tell the person exactly what method of 
paiement you can accept and how much the shipping 
costs. Then either the person agree or he doesn't 
and you don't sell him the item.

> 3) I've had people want me to 'fake' customs 
> forms to they don't have to pay their country's 
> taxes.

So what ? That form doesn't concern you but the 
customs in the country of the recipient.
Even the customs says that we have to put 
differant value : What is the real commercial 
value of a cel ? If there was less people bidding 
on it, you would sell it cheaper. So why is this 
value less or more correct than another one ?
Do you really want that much that people have to 
pay un-needed taxes ?

> It would be one thing if I were a dealer like
> you are Yann.

I wasn't always a dealer. Had to start one day...
IMHO, it's always the buyer that take the biggest 
risk : after all, he usual has to send the money 
first.

Naturaly, it's perfectly your right not to sell 
internationaly. But if you check with your 
bank/post office what method of paiement you can 
accept, there is no real reason.

Cheers,
Yann Stettler