I feel sorry for OP. It really sucks to be waiting on the receiving end of an invoice with no hope in sight of getting your hard-earned money. It really sucks to be in that position.

I don't know the specifics of this case, but I have encountered some of the same red flags that the author found. I worked as a remote contractor for a company, was interviewed over Skype by the CTO, had most of my interaction with the technical manager over Skype. I worked mostly by myself outside the scope of the other developers. Best of all, the codebase was mostly written by offshored developers.

This all sounds like a recipe for disaster, but instead it was an amazing experience. The tech manager was incredibly competent and great at managing umpteen developers in 4 countries. The codebase was reasonable to work with and I was able to move really quickly to get things done.

Maybe I got lucky, or maybe these red flags don't have any bearing. I only have anecdotes, so I don't know the answer.