I've considered those justifications/rationalizations myself. However, this exact argument could be applied to stealing from a physical store. Let me rephrase your statements slightly, to apply to physical theft:

"I wouldn't promote shoplifting to anyone else"
"The store is doing great; they won't go under just because I'm stealing $500 of goods per month"
"If the store would go out of business due to my theft, I wouldn't do it"

See how it's the exact same argument?

Another way of looking at it: why should all the parishioners (minus you) support the chapel, instead of ALL of you, or all of you minus ANOTHER parishioner? Why do YOU get to keep your money, while the other parishioners carry the place? After all, you all receive the same "goods" or benefit from the chapel. See the justice issues here? "A laborer is worthy of his hire."

PS. Of course, all normal rules apply as to how much you should contribute. For purposes of this discussion, let's say each parishioner should contribute "100% of what THEY should, before God, given THEIR specific circuмstances" In other words, let's pass over the issue of "how much should I contribute". That's why I'm keeping it generic "your contribution". We're talking principles here, not dollars and cents.

Uhm, you didn't say this before, just that the "anti-una-cuм" position was schismatic without any additional qualifications.  Learn how to actually make precise statements, would you?

False.  I cited some very clear examples.  It's actually the minority that are dogmatic "non una cuм".  Even the Dimond Brothers, dogmatic about almost everything else, are not.  Why don't you de-cloak from Anonymity so we can see who's pushing these lies.