While I’m not looking at doing so, I absolutely don’t want them stuck without heat, so I’ve purchased them 4 good space heaters which should sufficiently warm the home until my HVAC guy can get the install done.My tenants are wanting the problem remedied as soon as possible, but the replacement may not be done for a week and a half or two weeks.

You state "but the basic healthcare should be sufficient to cure or relieve any illness ..."

Having a HUD voucher may be  a tie breaker with similar applicants but is not a shoe in by any means.This is what we put on our application, for another example:Our Criteria:We do not deny housing for race, color, religion, sex, national origin, handicap, sexual orientation, marital status, or familial status.We do deny housing to individuals: when the application is not complete or accurate where there is not sufficient income/resources to pay rent and livewhere there is poor prior tenancy: evictions, violations, damage to rental property, poorly handled move outs, amounts are still owing to landlords or utilities.Criminal activity is at our discretion depending on severity, number of convictions, and how long ago.We do not go into much detail, especially since we don't charge for screening, but it gives them an idea and meets state requirements.

You have to be careful that your electric capacity is sufficient.

In best of circumstances, I wanted to see if a 3-day notice will be sufficient and valid or if the previous 60 day notice the seller sold would be grandfathered in after the purchase?

If you are looking in Texas, hire a Texas professional.MarkMark,However, your average Tejas attorney, and a good many of your NY attorneys are not going to be sufficiently current on Canadian {tax} law to be able to properly advise the OP on the best way to hold his U.S.A. investments as a Canadian.  

Should we fork over the money and get the regular inspection or is a rehab inspection sufficient?  

If they're rentals they could force your rents downward if they offer better value than your current units.The risk if they are for sale is that they don't sell at a sufficient margin above what you pay for your older duplex.

You shouldn’t have an issue purchasing a duplex with FHA. 3-4 units with FHA do require you to meet the self-sufficiency rule.

You can do an FHA loan in San Antonio IF the property qualifies for the self sufficiency test.