C) The worth of investing $30k in sweat equity, considering this is an out-of-state investment.I would appreciate any insights or advice you could give me on this potential investment.Thank you in advance for your input.

When you stop worrying about appreciation, you'll wander into markets that you might have avoided.  

I appreciate your feedback! 

Would it just be a double close to pay off the seller financing and I walk away with the appreciation and cash flow earned while under my control?

If anyone has any advice on what the best approach would be it would be greatly appreciated. 

I'm wondering if it would be smarter to save up for 20% down to speed things up but this will take me longer to get started  Let me know what you think, any advice is very appreciated.

We have properties on the far Northside (Libertyville - great appreciation, low cash flow, & low crime), westside (Cicero - Low appreciation, great cash flow, & medium hassle) and Southside (Greater grand-crossing - low appreciation, great cashflow, & high hassle)Are you asking for your own potential investing?

Some things that might be a concern:1) Obviously have to make sure things are all permitted first2) I don't want the room to "feel" like an addition, so flooring has to be same level/standardized with the rest of the house3) Unlike the rest of the house that has an identically-shaped 2200sqft basement underneath, this added space will not have a basement directly underneath it -- I'm not sure if this poses major cons for some reason that I'm not aware of4) Especially given the lack of basement underneath, I have to make sure that the HVAC can still somehow be piped into this room#2 and #3 are probably my biggest concerns (#1 and #4 I can find out relatively easily)Any tips/thoughts or other experience would be greatly appreciated. 

Greatly appreciate any advice.

I've also found good appreciation in these markets.