TheWizard

The Ford specs document says 2016 Edge width is 85.8" with mirrors extended and 78.4" with mirrors folded.
 
The PDF file is available here: https://media.ford.com/content/dam/fordmedia/North%20America/US/2016/05/23/2016-Ford-Edge-Tech-Specs.pdf.

I'm not sure if this is a serious question, but I'll bite...
 
The "blue water" is windshield washer fluid that is available from any auto parts store, dollar stores and most grocery stores (yes, and Walmart). I don't think Ford sells a premix washer fluid - they only have concentrate that must be mixed with water in the correct proportions. Most dealers don't even carry that. Every dealer I've been to just carries the same stuff you can buy anywhere because the Ford concentrate is inconvenient and expensive.
 
There is no difference between various brands that would make a Ford or Motorcraft branded fluid even remotely worth looking for. The concentrate is part #ZC-32-B for the 32 ounce container that costs about $10 and makes 64 ounces when diluted (with distilled water that you buy separately). That 64 ounces would cost you only about $3 everywhere else.

Almost all modern aftermarket head units have the wired remote capability that is necessary to retain steering wheel control. Then you need an adapter module that translates the steering wheel switch signals for the aftermarket head unit. Probably the best adapter module is the Axxess ASWC-1 which is self programming and will work with all major aftermarket brands including Alpine, Kenwood, Pioneer and Sony as well several others. It costs about $70 online.

No, none of the trim levels include any of the tow package components (cooling, sway control, hitch or wiring) - all of those components came only as part of the factory option 53G. That option is not a package you can buy and add to an existing vehicle. You could, of course, buy all the individual parts and install them but you have already seen that gets very expensive.
 
What are you planning to tow? The AWD 3.5L V6 is capable of towing 2,000 pounds without the factory towing package (i.e. just a hitch and the appropriate trailer wiring). That is plenty for towing a motorcycle, personal watercraft or small cargo trailer. The AWD V6 with the factory towing package is rated for 3,500 pounds towing capacity - significantly more but still not enough if you plan to pull a big boat or something. I would think that the sway control is not essential and is probably nearly impossible to add to a vehicle after it left the factory. The additional cooling of the larger radiator and fans is probably what makes the difference in towing capacity.
 
I have attached the 2013 Edge ordering guide which shows all standard equipment by model as well as available options and some technical specs.
 
2013 Edge Order Guide.pdf

a - There is a small indicator light directly above the Dual button
b - It should default to the last setting
c - No, when you enable it the two sides (dual) adjust temperature independently. Turn it off to adjust both together (single).
d - N/A

I have replaced all front and rear signal bulbs with LED equivalents. Cellbine is correct - the cheap bulbs don't do a good job of improving visibility over stock incandescent bulbs. Beyond that, different reflectors work better with different bulb types. For the '11+ Edge, I've found that the high wattage bulbs such as those "PlaZma" ones you found work well in the front but not as well in the back. The reflector of the rear turn signals works much better with multi-element LED bulbs such as the 45 SMD tower bulbs available at superbrightleds.com - they fill out the lens with a solid light that has a slightly sparkling effect because of all the individual LEDs.
 
Resistors are not necessary to make the LED bulbs work... they are necessary only to keep the turn signals from "hyper-flashing" to indicate a burned out bulb. However, I have found that the rear socket electrical contacts are not as tight as the front sockets. I had to bend the wire contacts on the LED bulbs outward to ensure good contact with the socket to get them to light up reliably.
 
You can buy LED bulbs with resistors built-in or you can buy higher power bulbs that draw enough current to fool the flasher module without requiring resistors. In either case, they are going to be much more expensive than $30 (mine cost $30 EACH and I have paid $50 each in the past). Otherwise, you will have to add resistors to prevent the "hyper-flashing".