1. Which programs should I apply to?
You should apply to a number of second and third tier programs, especially if you USMLE Step 1 scores are not outstanding.
2. What would you consider second and third tier academic programs?
There is no short answer to this question. I suggest you go to Doximity’s residency navigator and look at their list of surgery programs. You should start at the bottom and work your way up. Doximity’s list is not perfect, but it is better than any other one I have looked at.
3. How much of a level playing field is the interview process?
I’m not sure what you mean by this question. The object is to get some interviews. Most programs will not waste their time interviewing people they have no interest in. If you are offered an interview, you should obviously make the best impression you can.
4. What about observerships?
My understanding is that residency programs require IMGs to have "hands-on" experience in American hospitals. Observerships do not offer hands-on experience and therefore would not be acceptable. Clinical experience rotations can be expensive. I am not aware of any data showing what the success rate is for IMG applicants who have done US clinical experience rotations, but you probably will not be interviewed if you have not done at least one such rotation.
5. Should I apply for a preliminary surgery position through the match?
You should make a list of at least 30 or 40 [some IMGs tell me they have applied to more than 100] categorical programs to apply for as soon as the application process starts. If you get 12-15 interviews, you probably have a decent chance of matching. If you only get a few interviews, you should have a backup list of programs to apply to so that you can get that number of interviews up to the minimum of 12-15.
You might consider applying for a prelim position if you apply to a number of categorical residency programs and don’t get many interviews.
There were about 450 unfilled surgery preliminary positions in the 2016 match. Google "NRMP advance data tables 2016" and look at table 7.
You really don't need to apply to one of these positions through the match. However, if you are worried that you won't match to a categorical spot, you may want to apply to match for a prelim one to be sure you have something.
Most program directors will interview just about anyone who applies for an undesignated [meaning not already matched or planning to be matched to a subspecialty program such as orthopedics, ENT, or urology].
Remember, obtaining a preliminary position is not necessarily going to lead to a categorical spot.
6. What about applying for categorical and prelim spots at the same institution?
Think twice about applying to categorical and prelim spots at the same time and the same institution. That is perceived by some as a lack of confidence.
You may want to apply only for categorical positions at first. If you get very few interviews, then you can apply for prelim spots which are much easier to obtain than categorical ones. You need not be so eager to get a prelim position until you see how the categorical programs respond to you applications.
7. Should I apply to internal medicine programs as a backup?
Applying to medicine is an option, but once you start an internal medicine residency you are not likely to be able to switch to general surgery. In other words, doing a medicine residency does not enhance your application to categorical surgery the next year or even if you do a full 3 years of IM.
However if during the application process you don't seem to be getting many interviews for categorical positions and you are reluctant to take a chance on a preliminary position, you may want to apply to internal medicine or family medicine programs and abandon the idea of becoming a general surgeon.