If, instead of a Seller-financed mortgage, I opt for a traditional mortgage (assuming I qualify based on this ownership structure), would my lender restrict me combining the two units?  

What our degree, and knowledge, really brings to the table is how to handle codes and how to make amazing designs with those incredible restrictions.

If you already know the restrictions concerning delayed financing then just skip to section 3. 

There are quite a few restrictions with this - you have to identify the property you're exchanging to within 45 days or something like that.

@Andrew Boettcher Attorney fees to buy, then again for selling, ugh.I'm going to check the numbers to see if renting will cover my cost of ownership and check the HOA restrictions regarding subletting for a long-term buy/hold after living there for a bit. 

Too many restrictions on miles and cash in hand is more powerful (cash can be used for travel if so desired too). 

It's very unlikely that you can add additional units since there's already a second unit and new zoning doesn't allow - plus the setbacks of this current zoning is more restrictive than it used to be in that neighborhood. 

Neither the preceding sentence nor any provision pursuant thereto in a limited liability company agreement or certificate of formation shall (i) restrict a series or limited liability company on behalf of a series from agreeing in the limited liability company agreement or otherwise that any or all of the debts, liabilities, obligations and expenses incurred, contracted for or otherwise existing with respect to the limited liability company generally or any other series thereof shall be enforceable against the assets of such series or (ii) restrict a limited liability company from agreeing in the limited liability company agreement or otherwise that any or all of the debts, liabilities, obligations and expenses incurred, contracted for or otherwise existing with respect to a series shall be enforceable against the assets of the limited liability company generally.

So 7 can fit in that house unless your local jurisdiction has a more restrictive law.

If the local market is very hot, price it 5%-ish below the actual market value, restrict showings until the first open house, get all the buyers banging into each other at the open, solicit offers by 6 PM the next day.