I think your Uncle has at least most of it pretty close to right. Of course it's a general statement and shouldn't be meant to include 100% of any church or group, but I think he's pretty darn close. I also stand by my previous statement that religion and politics should be strictly separated, way more than any person on the other side of the aisle thinks church and state should be separated to protect the state from the church. Politics is poison, period. It's like hard drugs, everybody thinks "it's OK I can handle it" but it never works out that way, though I know many would disagree.
As for forcing churches to marry Same Sex couples I am firmly against it, as far as letting them get married, as far as legal rights, etc., goes I say why not? I've got enough to answer for come judgement day I don't need the guilt over keeping people apart who want to be together. I usually describe it as "My plate is going to look like Michael Moore's plate after he goes through a once through only trip at an all you can carry buffet line. I don't need one more chicken leg on there.
I'm not saying "it's OK" by God's rules I'm just saying I"m not going to try and stop them as long as they don't try to run over churches and ministers who don't want to marry them. That should never happen, but it will, sooner or later. As for losing tax exempt status, or any other sort of real persecution I think it would actually do the church good, or at least do Christianity good. We've gotten too comfortable (collectively) and we've placed too much faith in mammon and not enough in a being we claim created the world and can do literally anything for his people. Then look at these gigantic cathedrals all over the place, gigantic structures that make the Taj Mahal look like an army tent from the War of 1812.