Here's another dumb question,,,when you "jump" on the floor in that very area,,what happens?? Are the floors that weak they crack,groan, or excessively feel NON supported??
Fiberglass insulation isnt al THAT bad,let him do that and IF it doesnt cure the smell ,bats, and drafts,take tape off one side, foam it,trim that,,,and put back same type of tape same way IF you cant just peel back and reuse same tape. THEN landlord wont know,wont care till after lease is up and your GONE!! The foam should keep the worst of it OUT till lease is up. START looking ahead of time so your boxed and ready to go when the DAY arrives(Giving him proper notice of course)
A agree,,,calling the building inspector guys is a recipe for disaster without giving him at LEAST a couple chances. IF the bounce test tells you its READY to collapse ,,,THATS another story!!!