I have a duplex under contract that I anticipated paying $3,300 in annual property taxes (using the Indiana online property tax estimator), but they came in at $2,650...so maybe its already designated as a rental property?

People talk about tax deeds as a really scary thing, so I feel like I have to be missing something.Either way, it sounds like the quiet claim process is going to be necessary if I want to sell the property in the future (but maybe doesn't matter if I don't want to sell it?).

Either you always change locks at turnover (as I do) and it doesn't really matter. 

Does it complicate matters when planning to do a 1031 exchange?

It doesn't matter if they are accepted.

Does it complicate matters when planning to do a 1031 exchange?

I am going to set alarms and mail my marketing WEEKLY no matter what.

using it as  a STR or long term or vacation home doesn't matter .Miami/Broward pays about 1.9%-2.0% of the purchase price per year as an investor and 1.6%-1.8% for an owner occupant with homestead exemption.

Most often when agents get in trouble with creative financing it's a matter of not disclosing interests.When you do come up with a plan, you may want to run it past your broker to make sure you cover all your bases.

If the answer is a definitive "no", it doesn't matter how much interest you have in the property.