There are numerous more passive options that would project better COC.  

My property manager has contacted me that a tenant complains that numerous rats and a lot of rats poops have been seen at garage.The estimate for taking care of such problem came back with $900, which includes an assessment by sealing entire home and a 2 year warranty.What is the best and reasonable solution to this rat issue?

Call around, rates vary substantially; use an agent that represents numerous companies, not one dedicated to a single insurer; check quotes on-line to get a feel for which insurance companies are most competitive; sounds like you might be able to save money on insurance on your other properties as well.

I've seen numerous units where storage space has been converted into an extra unit.

There can be numerous tips and best practices which can smooth out your process @Claudine Stering 

@Blake Williams There are numerous factors to consider before anyone can give you a solid opinion:1.

Site-built homes have numerous areas in which to place utilities, and they usually don’t close the only escape route for occupants, as happens many times in mobile homes.”In addition, pre-1976 mobile homes had less insulation in walls, ceilings and floors, uninsulated air ducts and no vapor barriers in their roof cavities, making them an increased risk of fire hazards.

Your criteria should be dictated by numerous factor, your business, your goals, your rental property location, local real estate trends, types of tenants you want, etc..

I reached out toy local REIA and got numerous recommendations as well as vetting him against 3 others I got quotes from Those were all for 2.3.4 units however and I may have made a mistake thinking that because he has done well by me up till now, he might not be the best for commercial.

How are those of you, with numerous properties, shopping insurance on properties purchased strictly as investments and non owner-occupied?