When the VL homes were new I thought they had an agreement with RCSC for use of golf courses. Now they have an agreement with SCW under a program called Controlled Neighborhood Play (CNP).
When my parents bought a house in Ventana Lakes almost 20 years ago, they were told then the zip code would change to reflect not being a part of the community of Sun City. When my Aunt purchased there, she was told the same thing. Once again, I went to the USPS website that lists pending zip code changes and find nothing for Peoria/Sun City redistricting for this zip code change.
FYI, we do pay taxes into a general tax fund which is split among the public school system in our area.
During my time on the Board I spoke with many real estate agents, some were aware of the finer points of Sun City like the facilities agreement, difference between SCHOA and the RCSC. Others couldn’t find the corporate office with a map and a flashlight. The agent I had when looking really didn’t listen to me and my wants which really frustrated me. The saving grace was my agent was not the listing agent and we got along rather well when she realize I had a good working knowledge of real estate and transactions. I have also gone to open houses in the hood to see what was offered and how much they knew about Sun City. My experience was iffy. I am prepared to take the required course for a license and expect the same result as taking Civil Pro or Constitutional Law in the community college here. CM, when I first moved here my neighbor, Chet, asked how to tell a newcomer? They don’t have a real estate license.
Personally, I don't think it is RCSC's responsibility to get into real estate issues except properties that they own. Most of the incentives that you mention are offered by cities, counties or states.
Home equity loans are usually at least 1/2 % over the current prime rate but the interest is tax deductible if someone is itemizing their return. Those funds can be used for remodeling, renovating, etc. but it is still borrowing money.
According to this latest report there are 500,000 more home sellers than home buyers and the Phoenix area is number 7 on the list! I suspect that means many of the homes for sale in Sun City will now be considered to be over priced? https://thehill.com/business/housing/5326389-homesellers-outnumber-buyers-housing-market/amp/