Does that modification mean that someone who objects to the action described
in Section 2 would/could be deemed undesirable for that conduct?
As far as I can tell, yes. All that is required is that something about your character, reputation, or conduct might make you undesirable as a member.
"Might" is important here. Might doesn't mean "does". It means no proof is required. All that is required is suspicion that something might make you undesirable.
How is someone's character, reputation or conduct judged?
The board, under the proposed rule, need not set down any concrete criteria for reputation, character, or conduct. Reputation could be that you don't have the Worked All States award. Or that you do. Character could be that you like to wear blue. Conduct could be that you spoke in opposition to anything at all.
Is it a lifetime decision or temporary?
This is not stated, nor is it stated that an initial application for membership can be denied, rather than a renewal. These folks were not careful drafters.
Are there warnings prior to the judgement?
There is no requirement to even tell you that you were denied renewal, as far as I can see. Or that you get your dues back. Maybe they would not tell you, and then simply reject your vote.
This is very vague and confusing.
Uh huh. Perhaps you can see why I am so frustrated with the incumbent board and their conduct. So many things seem irresponsible and poorly thought out.