I would also be open to living in a fixer-upper and working on it in my down time.

If you follow this rule, you're less likely to run into financial trouble during down times, and it generally leads to better cash flow returns.  

This way they get temporary relief but do not get cherry reduced rent for years on end while the business recovers and makes tons of money and you get nothing for it.Generally in a settlement you are trying to get enough money to cover TI's, lost down time rent, LC's, attorney fees to put new tenant in where you are not coming out of pocket.

Also work out what 5% vacancy looks like in an 8 unit-number of months-allowing for some down time to renovate you should have quite a bit of difficulty hitting that number (that's almost 5 months of vacancies) I can't get close to 5% in my 12 unit building; more like 3% max and that includes some reno at turnover.Do your homework on the price, get an inspection and don't look back!

Plus you need to add in the down time for the unit.

I do not have enough money available put a cash offer in on the next project house until the first one sells, which causes too much downtime between projects.  

I have a fair amount of downtime when at work.

I was an early investor, mentored by my colleagues working selling Chevrolet's and most of the time there was downtime. 

I run my background check and have minimal downtime.

Likely no down time between tenants.