The man is a bully, attempting to intimidate you into (1) selling your condo to his friend and (2) keeping business between you two away from the Association President, who might hold him accountable for his shady way of doing business.
Bullies never like being exposed or being accountable to third parties -- it "embarrasses" them.
Just because you were thinking about maybe relocating someday does not mean that you are moving out now. This should be obvious to any reasonable person.
I suggest you show that note to the association president, and inform her that you have no plans for moving in the foreseeable future. Then tell her how much the guy creeps you out. At the very least, if he keeps harassing you, you will have a witness and a record of his aggression.
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No love for Hamas, Hezbollah, Iranian Leadership, Islamic Jihad, other Islamic terrorist groups, OR their supporters and sympathizers.