TLDR: don't trust anyone offering you a fixed rate of return, if it sounds too good to be true then it probably is. Great advice but very much over-complicated here.
It is true the OP used too many words to explain something really simple but I appreciate the effort he went through to explain as clearly as possible why it doesn't make sense for someone to offer you a fixed rate of return, the problem is that many people will still fall in that kind of scam because they are looking for a way to make easy profits without making any effort themselves and when you add greediness to that mix then it is obvious what the result will be.