I have the credit score and make a good monthly living but I have no cash save up but have 2 cash flowing rental properties with one of them having some equity.

The ability to do what you want, when you want, and have money coming in to support that.Things to work on: savings, credit, going to local real estate meetups, listening to podcasts, reading books.

Welcome to BP, sounds like you have a great track record and future!

Just to have the line of credit there if the opportunity comes my way. 

Well, this is harder than it sounds especially when you're a beginner because you know no one and have no track record.

Currently landlord pays for all utilities, is a system/product/device that can be installed to the water meter that tracks the usage of water through each unit so I would be able to bill the tenants separately?

Be sure to track your activities.

Your credit cards should be used as a last resort. 

(Couldn’t really afford the place, didn’t have good enough credit to be worried about an eviction, etc etc..)2) They should have posted a 5-7-10 (depending on local laws) to “pay or quit” as soon as the ent was late and started eviction.

2.For purchases made on a credit card, is it best to use separate cards, or are there good methods for tracking expenses by property?