when condo board business is disrupted by a bully, how do you get rid of him?

In CA anyone who is disruptive can be ejected. Condo board meetings here must permit a "homeowner's forum", a time in the agenda [which is posted in advance] for homeowners to speak, we can limit the time. We do this right after approving the minutes. After that the meeting is for business, approving a painting contract, etc. We can also adjourn to "executive session" but it is for specific business, not to hide.

It sounds like he is suffering from dementia. I understand your fear. You can talk to the police/sheriff in advance and ask for their advice, ask if they will come. You can use homeowner funds to hire private security. You can ask other homeowners who this guy has pissed off to attend and assuming the board has support, "shout him down", have the members tell him he is out of order, they don't want him to disrupt business. Even without explicit behavior written into your CC&R you have a reasonable expectation of civil adult behavior. Record your meetings for proof, then possibly get a restraining order against him. Use your association's attorney. Or hire one who practices condo law, a specialty.

Why does his height matter? Being in a conceal and carry state is not relevant.

Someone needs to stand up to him. When they do, he will shut his mouth. If he is being combatitive and disruptive, video on your phone and call police, police will remove him as a trespasser. No, you cannot ignore bylaws, BUT while bylaws give him a right to be in the meeting, they DO NOT give him the right to be a disturbance. Police.

Having a reverse mortgage doesn't mean you don't own. It's a lien on the property just like a regular mortgage. He still owns unless his name is off the deed.

A reverse mortgage does not change his ownership just as no other mortgage takes away his ownership. All owners are allowed at meetings. You as the president are in charge of taking charge. You have to be assertive and deal with it. He can only run all over you if you let him.

Talk to a (different) lawyer and learn what your options are.