Question: When Phoebe is on the phone with Ray, he mentions that the Ghostbusters fire house is now a Starbucks. In the post-credits scene, we see that Winston has purchased the fire house so the Ghostbusters can get back to business, but the fire house looks like it has been abandoned for several years and no other company ever took it over. Did I miss something here?
Answer: Perhaps nobody wanted to take over the place for a few reasons. Historical purpose, high cost... hauntings.?
Answer: It's been 40 years since the Ghostbusters disbanded, Ray mostly likely passed by the old place and saw a Starbucks there. It has since shut down.
But they left the ghost trap active? Not likely.
Question: How did Cecilia get an invisibility suit?
Answer: Cecilia went over to Adrian's house and found another invisibility suit.
Question: A helmet that is built to withstand thousands of PSI can really be broken by a few slams with a fire extinguisher?
Answer: Ray was probably being sarcastic, and was simply making a general comment about gentrification in the area.