I know Mat. 5 as well as you did - and I did not cite it. I cited Rom. 14:4, 10 - who are you to judge another man's servant? When we see sin, yes, we're supposed to discern that it is sin; it is forbidden to us, however, to even criticize the man who worships God in a way we don't like. Among the issues forbidden to judge in Rom. 14 is rituals that some observe, but others do not.
(Also, long cut-and-pastes of entire Biblical chapters is not useful. Pinpoint citations make for a tighter, cleaner argument.)
Actually that passage is only about eating meat. It doesn't talk about any rituals.
I think it would depend on what significance that the ritual has. If someone believes that kneeling before their front door on glass three times a day will give them more grace from God (ridiculous example, I know) we have a right to say, biblical, that is wrong. Grace is a free gift of God, not merited -else, not grace.
As to Romans 14, the context is not judging people weak in faith who have certain practices. We don't want to be a stumbling block to someone's growth. But if their belief is clearly unscriptural and is leading them in the wrong direction, those who are stronger have the obligation to point the error out and try to lead the person back into the right path.