Tenant doing business like activity

[Roman S.]

Hello fellow landlords. I have a tenant in TN that has been gradually building a pretty extensive garden in the backyard (property has a huge backyard) and transformed the garage into the green house, where they grow lots of starter plants. They seem to be pretty professional about it, in terms of cleanliness, organization and safety, but you never know. They are also an exemplary tenant without a single complaint or work request. But I am wondering if my insurance would cover if they accidentally damage or burn part of the house (due to the extra wiring and lights in the garage)? This is not exactly running a business (because they sell these elsewhere) but they are using the premises to run business activities... Safeco's independent agent wasn't sure (she's still investigating), but I am wondering if anyone here had a similar experience and how they went about making sure they are properly protected? 

My other concern is related to the extensive changes they are making to the property. PM asked them to slow down, but at this point I doubt my 1k deposit would cover the cost of changing everything back to how it was in the backyard and garage. Should I increase the deposit/rent? Currently, the rent is right around average for the area. Any thoughts or advise is greatly appreciated.