Although cashflow is important, it is now always the only component to consider when looking at a long term real estate strategy.

The most important criteria to most sellers is the price.

So whether you are renting to families, individuals or businesses, it's important as a property owner to require your tenants carry liability insurance.

Second lady got a new boyfriend and he moved his kids in, and they decided that partying was more important than paying rent. 

As long as you're happy and making money, that is what's important. 

I have often heard of how important it is to find someone who you can trust to help you start out.. so this is important.  

It depends.it depends on your investing strategy, it depends of what market your investing in and most importantly it depends on you goals. for example one investor can say i like working with people in D areas so im fine with 6% COC return but my ROI has to be 20% in 5 years.The next investor that wants turn key properties SFR with 10% ROI wouldnt wish that criteria on their worst enemy.So what people say on here wont help you make a decision about your criteria.NOW that being said heres my 2 cents!

The communication element is important, especially if you're managing your property with a spouse, family member, or a property manager.

I know that it's supremely important to show that you are not the business and the business is not you, in order to prevent piercing the corporate veil. 

The most important thing when starting out is to get good training.