Should I Go for 4 Premolar Extractions + Braces to Correct a Mild Profile Protrusion?

You don't have maxillary protrusion, you have mandibular retrognathism. If you extract four bicuspids you will be fitting your maxilla (that is already in the correct position) to your mandible (that is currently in the wrong position). 

Your ideal treatment would be to bring your mandible forward. This can be done without surgery with an appliance that you wear. Bringing your mandible forward will give you a much stronger chin which will greatly enhance your facial profile.

You will be extremely unhappy with the way your facial aesthetics will look after extracting four bicuspids; please find a doctor who understands that your problem is the position of your mandible NOT the position of your maxilla. You might require some maxillary development before the mandible can be brought forward but this too can be done without surgery using a simple appliance.

Extracting four bicuspids will also potentially compromise your airway, upper lip support, and TMJ; plus your smile will be narrower and much less aesthetic.

Good luck!

Just read the review from the doctor who made a big deal about the fact that this patient has a "small" lower jaw and that "traditional" orthodontic treatment could cause all sorts of problems.  The problem here is that there is absolutely no scientific proof that any appliance can routinely "grow" a lower jaw forward a significant amount.  Ask for proof that his type of treatment works (not anecdotal case reports) before accepting this type of treatment....most orthodontists are not crazy or stupid...if there is a better way to fix problems we would do it!