It would not be wise to leverage in any situation, in my opinion, without adequate reserves for the unexpected, however.

To get there I am working on increasing my income and reducing my daily living expenses.I had a massive personal budget overhaul about a year ago and reduced my expenses as much as I could, all expenses are planned and budgeted and I know exactly how much cashflow I have each month if there are no unexpected expenses.Part of that is I am focusing on flipping/wholesaling property to build more capital and then use it to buy more rentals as well and focusing on increasing my J.O.B. income until I can do REI full time.I think either route can work, buying only rentals may be a little slower at first but if the equity and cash flow are managed well it can increase more and more.

You can built that back up...or the "worst case" is you take out a <insert form of debt here> if you have an unexpected cap-ex expense come along. 

My father passed away a few months ago unexpectedly at the age of 52.

Remember you will need your 3.5% FHA down payment and cash reserves for unexpected repairs/ vacancies.

Are some experienced investors reading this and predicting failure due to an unexpected maintenance issue, or failure to manage my manager?

PM reports new and unexpected CAPEX expenses and turnover fees and property becomes cashflow negative.4.  

This would expose you to liability or possibly having to unexpectedly buy him out to pay off his judgment creditor.

Reserves of 4 to 6 months depending on the size of holding is something that would be a good idea,, you never know when a eviction, turn cost, or unexpected repair is going to be a cost issue.. and new landlords aren't usually prepared for them.

Couple of ways to improve the accuracy of your numbers:Consider adding vacancy as a % (typically 5-10%) because it's impossible to keep all unit 100% rentedNeed to add CapEx for your future big costs (roof, HVAC, etc)Considering adding a reserve for any other unexpected expenses.Keep up the good work!