Can you please help me with a couple of other basic Qs -- 1) What kind of "system" do you follow for delivering time sensitive notices with hard to reach tenants?      

I would certainly recommend verifying that they can afford the monthly payments as you do want them to purchase the property as soon as they can qualify for financing; you're just safeguarded in case they don't end up purchasing.

Therefore, the market is very sensitive to any crisis or recession abroad, especially in North America.

House has been rented out for a 10  years  to the same tenant, want to be sensitive yet efficient.

While you want to be sensitive to the situation, a rental property is a business and must be treated as such.

Anything thinner will telegraph the highs and lows. 2) if you need or want to glue down and heat or moisture is a issue, DON'T use a pressure sensitive adhesive EVER!

Cheryl,My experience is that they can be great tenants but tend to be very price sensitive and we make better margins when we just rent on airbnb.

You can definitely employ some additional safeguards (higher deposits, guarantors/co-signers) but at the end of the day it is a risk that you will have to take knowing that her financial history isn't polished.

I am targeting a minimum 7% cash yield for new acquisitions and I sensitize all underwriting assuming a larger op-ex ratio and a larger vacancy factor. 

If there's a hole, it may be a red flag.b) sensitivity analysis: I examine all the assumptions, and make sure I can live with the worst case scenarios.c) "Stall and see": if they are getting money over multiple years, and there is no penalty for investing later, I would usually wait so I get some real performance data, versus having to look at theoretical pro forma information.d) Recession stress test: I will not invest in anything, until I subject it to recession level stress and see if I can live with the result.