I know the 401 penalties are steep but my thoughts are if I can gain enough cash flow to leave my current career, do I really need to worry about whatever money is in there to draw from 20 years down the road?

I plan to leave them enough that they can afford to buy a house or start a nest egg, but I am not leaving large sums to them.

Don't leave this option OFF the table. 

There are a number of strategies that could be taken with the property that would meet my goals so I wanted to leave it open ended so as to not discourage people from chiming in with their thoughts and ideas.  

You are in Boston, if you found a 5 cap in Beacon Hill how quick would that leave the market?

So what do you do with the houses - leave them vacant?

I think it's ridiculous to pay a tenant to leave, but it makes sense in places like California.

When you do that, you can get better pricing and leaves less room for error.The best advice is to push forward as quick as possible, fail forward, and always continue to introspect on what you would do differently and then ACTUALLY go back and implement that change (easier to say than do).

Last question, how significantly would the APR improve if we leave 30% in vs 25% or 20% on a HELO? 

Leave out the emotion, the lies, the manipulation, etc.