Many condo associations have restriction on the number of rentals.

Are there any restrictions to doing so?

Also, depending on the site and zoning restrictions, construction costs may vary due to building classifications. 

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.