The HELOC seemed easier with less fees( I had to pull out a certain amount of money but put it right back in).  

Can I pull comps (CMA)  with one MLS system?

When I have completed the renovation, can I pull the forced equity out and use it toward another home while collecting the monthly payment and putting toward the equity refinancing?

The taxes around my area are typically high and I pulled that number off of Zillow.

I believe they have a subscription system however from what I recall it's a little bit expensive and is not very user friendly.You can pull the public data from the various websites and then go and extrapolate everything, but unless you've got a pretty good programmer who can build out some engines to go scrape everything you will end up doing a lot of that mining manually.

Finally if you wanted to, leverage Baltimore home to pull cash out and buy a 3rd investment property.

Here is what the mortgage on the property looks like and what it would look like if we chose to pull the trigger.

Without a goal you are basically pulling tools out of the toolbox without a gameplan. 

From what I've seen, you could always consider networking and partnering with a real estate agent that would be willing to pull comps from the MLS for you.

The 50% rule is good to consider, but if you're able to pull data to break down the expenses further to get a better idea (area taxes, insurance quotes, PM %, etc) it'll make things more accurate.