I understand what you express JK. I know such issue over stumbling others is repeated in other parts of the new testament. However, what puzzles me is the change in par 22. (Bolds mine)
The faith that you have, keep it to yourself before God. (Now switches to third person) Happy is the man who does not judge himself for what he approves. But if he has doubts, he is already condemned if he eats, because he does not eat based on faith. Indeed, everything that is not based on faith is sin.
What do they mean by "Happy is the man who does not judge himself for what he approves"? Does it mean that our confidence on our belief set us free from guilt?
The rest, I see it this way. In those time when pork was considered unclean, a man who was converted to "the truth" could now understand that he was ok to eat pork. However, he may not be fully convinced or have faith that he was doing nothing wrong. If he went ahead and ate anyway, doubts and all, then he was comitting a sin. A man who was reassured of his belief and ate without guilt, was therefore a happy person. All of this, off course, so long he did not stumble anyone who saw him by doing so.