@Charlie Moore assuming all 5 of them met all of your rental criteria (since you said they were "fantastic") then I'd go with the one you received a completed application from first, and for the rest of them send a short email or txt like @Nathan G. suggested.

I'd be glad the mirror did not break when they lived there and caused them bodily harm.Yes, the tenant response is over-the-top.

A lot of the other duplexes and triplexes in the area have shingles and a lot of them have metal roofs so as far as getting renters neither one will really deter anyone.

Because the risk is lower (because the borrower met all the guidelines), the rate and cost is lower.The next level would be portfolio lenders. 

Unless the surface is a factory finish or a baked on metal type finish.

I work as a welder metal fabricator 9-5 and my wife is a sales associate.

If all you have is a masonry facade over a fireplace unit, which is what it sounds like if you have a metal flue, like for a gas water heater or furnace, it should be an easier removal.

Plaster, in my neck of the woods and target properties, is always plaster-on-lathe, usually wood, very occasionally metal.

I personally know a friend of mine who called his insurance company and they paid for a metal roof, they had no damage but the adjuster said there were few damages on the shingles( he had shingle roof).

Example, we stopped buying barstools that have nuts and bolts to tighten and switched to a single piece metal design.