As such, do we need approval from all tenants to spray inside/outside? 

Open some windows, spray some febreeze and run some fans.

While you've got the window casing apart, take a few minutes & put some insulation or spray foam around the framing - it'll make a huge difference in stopping drafts.

I'm always looking for suggestions to improve it.Too many investors have the spray and pray mentality and throw ridiculous amounts of money on direct mail, SEO, cold calling, etc without focusing on the issues that are causing their budgets to be so high.

He spray paints the entire bathrooms including the tile walls and bathtubs with whie paint.

That is the only extra charge and he looks for them on his quarterly spray.   

The exterminator for example just calls them when its time for a quarterly spray and they work it out themselves.

I would be cautious with cheap no name companies, because they could come spray water around your foundation letting you think they are “treating” the place and in 2 years when your place is eaten up, they will be out of business.

It's spray and pray.

Next I spray my wife's perfume on it, then in the mail box it goes.