The question that keeps stumping me is, when I refinance the original loan to take the equity, would that not raise my mortgage payment on the original  house, therefore cutting down my potential profits on the next purchase?

Will the IRS only come after what is left in the 401k for their cut?  

You will want them to hold open houses, screen tenants well, cut costs on repairs, do basic make readies in 3-5 days and big rehabs in 2-4 weeks.Often properties can stay vacant in the winter time in Ohio for months at a time. 

Always do the math analysis and try to look at your prospective properties before you make an offer or at least have a clause in the sales contract that allows you the time (10 to 15 days) to make a entailed inspection of the subject property and possibly back out of the deal without a penalty that hurts you too much.Do not cut any corners on your evaluations to make them look better on paper but not in reality.  

After much back and forth, the agents cutting their commission, one agent paying for a washing machine out of pocket, three rejected counter-offers.... we ended up at $603k.

Michael, Your best bet is to partner with a builder and take a cut of the building portion.  

And condos with HOA fees are going to continue to cut into your returns/cash flow.

Try to run a single non-deal by an experienced buyer and you will likely be cut off their contacts list instantly.You will likely need to not only go "off market", but you will also need to learn ways to look off market that the other thousands of wholesalers and investors aren't doing.Get your RE license.Learn to structure your offers in multiple ways and have multiple ways to help people.

I took pictures of all kinds of issues: damage to most of my new cabinets they installed, electrician replaced a bunch of new lights and fan I had a prior contractor put in, wood trim was installed poorly unevenly cut, drywall finishing looked terrible, the plumbing they roughed in didn't line up with the vanities they knew were there to be measured... among many other issues. 

It seems pretty cut and dry.