Long ago, I actually rented a one bedroom apartment in a red brick quadplex built around 1920, I was on the top floor, and the flat roof started to leak in the closet, didn't notice it right away until I had respiratory issues.

I'm not sure if handyman coming during the day could prevent pipe damage or a leak anyway?

For example, while the tech is checking the plumbing voids for pest droppings, you can look for leaks.

I had a tenant who's mover removed the hoses from the washer when they moved on the 3rd floor but left them hanging from the faucet and it leaked onto the wood floors below causing them to need to be replaced since it was not caught for over 24 hours. 

Just a guess here, but you have had some leaks above that ceiling...either roof directly above, or plumbing leaks from the unit(s) above, showing staining or active leaks over a period of time?

The problem with too much expansion, is that it starts to expose leaks and the larger the team, you lose out on quality.

And roof leaks quickly turn into mold problems if not fixed right away. 

Same thing with sellers who have assumable mortgages at low rates.Some folks have been talking about "subject to" more (where you buy the property with the old mortgage in place and don't tell the bank) but I'm personally very reluctant to go down that road as it's seemed banks have gotten much more sophisticated about detecting changes in ownership, particularly regarding the named insured on the property insurance not matching up with the borrower's name.Like seller financing, "off market" deals are also good in any market phase, and are looking even more attractive in this phase... if you get a realistic seller who's willing to play the "you set the price, I set the terms" game.

You can make and get reimbursed for preservation and safety of the property if they redeem...for example fixing broken windows or bad locks....repairing leaking roofs .

And don’t worry about cosmetics of the house unless it’s bad, because appraisers are supposed to deduct the value for immediate repairs aka deferred maintenance (I.e. brokers windows, broken appliances, leaking roof).