Back then, if the apartment is in good shape, no painting needed, I could show it in June while the tenant is there, and even rent the place out by July 1, without losing any rent.But now, having done rentals for a while, the stress on both me and my tenant simply isn't worth it.

It is a lot to consider, a lot of work, a lot of hard work and long hours getting started.One of the factors I stress very strongly is to learn all your state landlord tenant regulations before you purchase your first rental.

Reading the responses definitely calmed my concerns and relieved the stress of it.

-For stress testing, I'm a bit conservative and want 65-70% LTV and 6-12 months reserves.

We stress followup heavily in our business model. 

No need to stress about my second property before even owning my first, but I'm just trying to keep my dream in mind of house hacking a new building every 3 years or so until I no longer step into an office every morning by the age of 40 :) 

I don't want another stressful job.

Your goal is to find the people that will work with you and not to stress over the people that won't. 

We'd planned for my sister to be the PM but then life happened (layoff, new job with travel) so we decided she didn't need the extra stress.

It was very informal, I stressed about it, prepared spreadsheets, comps, etc and I'm glad I did for my comfort, but it wasn't necessary.