Sometime later this year (hopefully around May) I'll be making a return. The reasons for people falling through objects and cars not being able to spawn is not a problem with the map, but with the streamer and the way RS5 vehicles spawning script has been created (FBI HQ LS as an example) - at least that was the case when I was active.
As stated, the prices of properties are not meant to be that high and this, among many other issues, is the reason why people don't want to use the island. I still have Phase 2 saved somewhere, but I'll have to speak to Teddy when I return to see if there is any point in continuing the project.