I heard the Uber business was really starting to boom over there.

lots of folks who do real estate full time run, or own, a business, and so that's their 'work.  

They understand bulk business and typically like to work repeatedly with the same people to keep things easy. 2) It's easier to negotiate with subs.

I am looking for an online-only business banking solution that offers:1.

It would be valid to assign the business account under the name of the owner who is more actively involved in managing the property.

In Canada, even thru this structure we get 8.5-9.5% net returns being passively invested in mortgage funds.  

If you want to value add you are better off with a structurally sound unit that is priced low and you can rebuild from the ground up front loading the risk.  

If your goal is to flip and you get good at marketing, you may end up with a wholesaling business, but I wouldn't try to build a wholesaling business.

I read over a sample personal umbrella insurance policy and it says that they dont cover injury due to business property, and that business property is defined as residential property rented, or held for rental, to others.

Talk to your CPA about how to structure this as a failed investment or something to offset your w-2 income.