By having the equity line available, you can potentially borrow against one house at any given time to buy another house at a good buy with the proper credit. 

Thanks for the reassurance on this issue, have you found that proper maintenance in an older building is more expensive than in a newer property. 

You also need the proper mix of credit.

I think it is definitely wise to take your time before leaping into any investment, all things require the proper research and due diligence.

All systems must be properly maintained on an ongoing basis.

I had found where they were living so could get the documents delivered properly. 

I still think SEO works when done properly.

The city is taking action for "lateral" earthquakes, an example for this is on concrete basements, these doesn't apply, because there are shear walls below the building to hold its weight. 

You are buying current rent rolls not projected rent rolls therefore you must price the properly accordingly   Getting the rent roll is easy.  

You need to use proper legal notices and follow the landlord-tenant laws for your jurisdiction.