Forming an LLC for Foreign / Non-US residents ?

Hello,

I'm not a US resident and I'm making an order through Legalzoom to file an LLC in Florida. They will act as my registered agent too. The problem is that I have to insert a US business address (Not P.O. Box) which I don't have because I'm not US resident as I mentioned. So, I came up with two solutions. First, to use my relative's residential address in Illinois as my business address temporary in the filing. Second solution is to apply for a US business address service (Not a virtual office) like the service provided by "Mailbox Forwarding" at an affordable price. They say that various international companies use their address service as their business address.

I have couple of questions, hope anyone can help me find the answers:

1) Can I use my relative's residential address in "Illinois" without need to file the LLC there or I must use an address in FL (Where I'm filing the LLC) ?.
Someone told me that if I used the address in Illinois, I must file there and pay IL taxes too.

2) Would it be better if I applied for the service provided by Mailbox Forwarding and use their address in FL?

3) My business is online based, selling non-tangible products and services through my website. So, if we assume that I sold one service in 5 states (5 customers), that means that I have to qualify (or file) my LLC inside the five states and pay their taxes?

I hope that anyone could answer my questions. Any answers would be appreciated and thank you for taking time to read this.
Best regards.

 

Why not form a company in your country and pay taxes there?