Unfortunately most of what you say is a myth which may at one time been true...but no longer is. Among what we consider 1st world countries, we are dead last in the area of upward mobility.. meaning if you are born poor in the USA, you will more than likely remain poor. In fact.. ours is the first generation whose kids will likely not be as well off as we are. It is nearly impossible with the present "deck stacking" for a poor or middleclass individual to move into a higher economic class.
Also... the notion that people are flocking here in droves is a myth.. In fact the US is now at a net negative immigration rate... ie more people are leaving than coming. and are predicted to continue to decrease.
As for freedom to worship... that may be very true... however, I would have to ask the current population of Muslim citizens how comfortable they are being made to feel.. OR people who choose to NOT practice a religion... how are they looked at or treated?