Can I detain you against your will? No. That is an overt act which harms another person. That is not permitted on either private or public property (unless of course, you have attempted to harm me and I am detaining you while awaiting the police)..
Can I forbid you from practicing your religion on MY private property? Yes - to the extent that I can make you leave if I do not like your religion, or for any reason I choose, or for no reason at all.
Can I require you to observe my religious beliefs on MY private property? Yes - to the extant that I can make you leave if you refuse to observe my religious practices, or for any other reason I choose, or for no reason at all.
I probably won’t end up with very many friends, but that is not the issue.
The Constitution restricts the government, not individuals on their own property. The Constitution respects private property.
Yes!
I agree with every point you made...
I think you need to qualify this statement with a demurrer, something like:
". . . if it is open to the general public."
Even the police are not ordinarily welcome past the threshold of my property unless (a) I invite them, or (b) I am holding an "open house" event. Is this not so?