Now, some of these answers will depend on what state that property is in, how much equity you have, and a couple of other factors...but you can certainly seek out other lenders about a Line of Credit on an investment property.  

Another factor that works well with US investors is that the local currently AED (Dihram) is pegged to the USD at 3.67~ AED per 1 USD.For long term rentals, its on average 5-8% after the “Service Charge” reduction.

I found out those two factors still couldn't guarantee they pay their rents on time. 

@Nik Farooqui You are correct in that GC licensing is never a requirement but it is more of a "silent factor" that can make a lender more comfortable lending hard money and thus the approval and loan process easier.

If think you'll have capital expenses I'd factor those costs in. 

Any more than this, and I feel that I am paying for their luxury lifestyle before getting returns delivered. 

I planned for it financially, but it's a headache for sure. your rent is too high if they are sitting vacant.. there is more inventory than butts to put in them.. therefore competition for the few qualified tenants this will cause rents to go DOWN.. if a property is not rented in 2 to 4 weeks your rent is too high .. this is one of the major risk factors that many dont see when buying in a subdivision of group of ALL new rentals..

I agree that these are more important factors.

There are two types of appreciation to consider:1.Market Appreciation: Rising property values driven by external factors like economic growth, demand, or market conditions.

There are a lot of factors that go into this and a lot of levers to pull.If none of this works and the goal of the new purchase is to househack that property into an investment property, you may be able to use a DSCR loan to buy the new property as an outright investment property.