Although the age difference and no wedding ceremony is a red flag, in your case I do not believe these would be viewed as red flags. You have been waiting a while now, but I think your last delay is the re-medical request, in all honesty the VO should have just extended the ones your wife did previously. I would not be surprised now that your wife did the re-medical in December that you will have a decision made this month. I certainly hope so!!!
What bothers me is that the CIC policy should be applied by all visa officers, for example the extension of medicals, some visa offices do it more than others, and often they extend for a 12 month period without a re-medical request, saving time and money for everyone involved. Than you have some visa offices that are notorious for requesting re-medicals in each and every case. There is just no rhyme and reason to how policies are applied, and it makes the process very unfair.