Since you're in Akron, be very careful of the area you are purchasing the 4-plex in.

This entity may require the filing of an entity return depending on its structure.Furthermore, it depends on how well your wife does the books.

Question 1: Even though we are careful to track ALL rental expenses that are paid using our personal credit cards, is that enough separation from personal accounts or MUST we open a separate credit card for each LLC? 

These tenants usually have a decent credit score and care about keeping it that way.

Would love some kind of an online portal for this sort of thing.Thanks!

Did I care in the beginning ?  

Buy within your comfort level, but always know no one is going to care as much about your investment as you do, so make sure you are mitigating the risk of OOS as much as possible.

But sometimes, it takes careful selection and interviews to get the right person.

The concerns come into play if your parents are buying as part of an exchange,

Is it better to get a property management company to take care of them or split them?