If not done well can cause ongoing problems. 

The plumber should be able to write a couple sentences describing what they found and what they determined the cause to be. 

Any of those expenses could wipe out cash flow and cause negative reviews.

Because of the ice buildup, I was considering it as a risk factor because even though it is 25 feet long  (maybe close to 35 feet), its very steep and if the tenant is not very careful then it becomes a situation where they may cause or get into an accident while driving down the driveway onto the road.

@Brad Larsen would you share what reasons caused you to switch to Appfolio?

I had to look into a different policy for my own coverage (CBIZ) and I feel that this would cause some owners some issues...

Make sure your tenants are making other arrangements, either on their own or through the Red Cross (their Renter's insurance should provide them lodging, and, if they caused the fire, might handle some/all of the restoration).

Rather than worrying about whether or not it is a violation of building code, I'd work on figuring out how to fix it before it causes more problems. 

Does this cause any problems with taxes if i'm writing off most of what I'm spending for the renovation?

A treadmill doesn't cause a ton of noise/vibration/shaking.