Does selling IPTV subscription is legal in the USA

I don't know what IPTV is. The sale of certain goods is regulated in the US.

Letters in my possession for 30 years written to a cousin who lived with me -can I use for a book?

This is an intellectual property question. Pass to that area.

You don't specify how the contracts will be set out, but at some point you may face some US tax withholding. Not to worry; if some company does...

Any US immigration consequences for non-US citizen who invests in securities of US and Canadian Cannabis/Marijuana Companies?

This is an immigration question. Pass to that area.

Can I sue on behalf of the artists I sponsored 5 months ago ?

You really need to consult a lawyer in the pertinent jurisdiction (California) to see what your rights are. I assume it would depend on the...

Can the USA government take your international property to pay a fine

Your question is rather broad. Generally, the United States, as an entity and like any other party, may file an action in a foreign court seeking...

I have a friend who lives in Panama/Central America. He's Venezuela and wants to become a US citizen.

This is an immigration question. Pass to that area.

Can my K1 pending fiancee travel to Guam or enter Guam to begin with?

This is an immigration question. Pass to that area.

Can I travel international if I have a out of state DUI warrant from 9 yrs ago

It is quite likely the warrant is on NCIC and you will be arrested at the border. My advice is you clear it up ASAP>.

Can Power of Attorney be used to close/open bank accounts?

If she needs a US notary, the Embassy or a US consulate can do this function. Generally you have to make an appointment. Banks are very persnickety...