Read your governing documents to determine whether or not this board action requires an owner vote. There is no standard.
A homeowners association cannot be a mandatory association without the consent of 100% of the property owners in the development attempting to establish an association. In addition to the consent of the property owners, the association must follow certain procedures and file the proper documents in order to subject the property to the association's rule.
The board can work through the business case of removing a swimming pool. As well, the governing documents may dictate an owners' vote percentage be required, since removal of a pool significantly adjusts the value of amenities in the association.
Norwegian Forest Owners Association was created in 1913.
National Association of Theatre Owners was created in 1965.
Without Majorty Rule, The Bahamas would be filled with slaves an white owners.
Not without the consent of the person the information concerns. Without consent the association is breaking the Data Protection Act, or a similar law depending on your country.
National Association of Women Business Owners was created in 1975.
Read your governing documents to determine the process required to sell part of the common area. This may require an uber-majority of owners' votes, an amendment to your CC&Rs and so forth. Your association's legal counsel can answer this question specifically.
They can if the streets are owned by the home owners' association rather than by a municipality.
If the association's governing documents require a 90 percent majority as a vote to approve a matter, then that is what is required. A simple majority does not satisfy the 90 percent majority requirement. Generally, the 90 percent majority indicates a majority of owners. No even a simple majority of board members can overwhelm this requirement.
I don't see any need for liability insurance in the case you described. In cases where you have a homeowners association or a condo owners association and they own common property such as a swimming pool, parks, roofs, sidewalks, etc. then they would have a need for both property and liability insurnance to cover these areas. This is what you dues are in place to pay for as well as maintenance.
Property Owners' Association (similar to Homeowners' Association)