On an annual basis, the administration is mostly meeting minutes, resolutions, and annual filing of your 990, most of which can be outsourced depending on your budget.

Expect to spend a considerable amount of your time speaking to people.Expect to work dozens of hours/week with little to no immediate result.Expect most of your early interest from potential clients to come from your sphere of influence.Expect to go 3-6 months without getting paid (unless you do rentals which usually pay faster)Expect to be bombarded with distractions - mainly, people/companies marketing to you so that you choose their system for quick and easy buyer or seller leads.

And this does not include the real world issues, namely are you even allowed to convert this property to a four-unit and taking a single family to 4 unit is very likely going to cost more than $110k (but this depends on the actual layout and work scope).

If they are able to remove the term it will be dependent on the loan underwriting requirements, not because they want to keep you as a banking customer.

Use private money lenders and choose a conservative market.

As for cash or not I think it depends on rates, your level of risk tolerance, and what the opportunity costs is for that money. 

Depending on your state you may or may not be allowed to accept a partial payment during the process.

It varies a lot depending on install method, regional area, heck even a specific properties weather exposure. 

You'll most likely find your staffing costs to be in the neighborhood of $1,200 to $1,900 per unit per year, depending on property size, class, and market. 

As Pari said, you can learn notes and earn more than that, or if you want mailbox money and do no work, JV with a note investor and you can get 12%+ and your money is not tied up for years but on average 12-18 months (or less) depending on the deal.