Replace my 2nd molar (extracted) with an implant or pull my wisdom tooth with braces ?

It is very hard to say from your picture but it is possible you have developed a dry socket.  Contact your oral surgeon and tell them what is going on and that you would like to be seen.  I am sure they will take care of you.  Good luck!

Long span bridge with two teeth supporting the dental bridge has GUARDED PROGNOSIS.You are having a 6 unit bridge, with 2 abutments , meaning teeth supporting your bridge, in area which you chew, I would be hesitant to go that route.Why don't you have dental implant consult ? if you do not want...

The longer you can hold off the better but the first 24-48 hours is crucial. After this time period the blood clot should have formed and healing has started to occur. Although smoking at any time will still delay healing after the 48 hour time period you should be fine. 

It sounds like a chemical or allergic reaction to the mouthwash.  First, you should not use it again.  Warm salt water or tea can help the area feel better.  There is a perscription product called Gelclairwhich is almost mraculous in speeding healing and instantly increasing comfort.

I would suggest seeing a board certified oral and maxillofacial surgeon. They are experts at wisdom tooth and broken tooth removal and should be able to offer you options for sedation so the experience will be as pleasant as possible.

The simple answer is no.  The third molar area you have on photograph most likely represents a mixture or healing tissue, blood clot and possible food debris.  Dry socket is ussually with progressive pain that continues to worrsen as several days pass.  Having pain while biting...