I would then plan to use this forced equity (since I plan to buy a fixer upper) to invest in another home.I have been constantly reading to househack right into the MFH, but this may take some time for me to acquire the money and purchasing power.

Have you decided on a target market that you plan on investing in yet?

I am planning to purchase a property subto the existing mortgage (50k left) and current tax lien (65k).

Are there any potential issues with this plan?  

A super ball number to get you going would be at least $190/SF-$220/sf ish... to figure out square footage it's probably best to connect with a Chicago architect like @Samuel Pavlovcik or @Prashanth Mahakali both can talk through the zoning and plan development process.

Also, you're able to keep the loan current if you're planning to keep the seller's name on the mortgage until it's paid off.

I plan on building a duplex (so 2 kitchens and 2 living rooms).

This question is asked a lot and there's a ton of value by just reading those previous conversations.In short, there are pros and cons to the program.

I have insurance either way, but he said it's still best to split them up, with each having their own LLC.My plan is to create a new LLC for each one:-123 MAIN ST, LLC-123 GREEN ST, LLC...and then use my original LLC as the "Holdings Company", which then owns those 2 LLC's, and any additional properties I acquire.As of now, I have 1 business credit card and 1 business account for *JOHN SMITH PROPERTY INVESTMENT, LLC* -- this makes things easy from a bookkeeping standpoint.

It's not a flat fee for me, but I probably have the most basic plan -- I think it's $8 for up to 200 pages/month, or something along those lines.