My answers below are on the assumption that your F1 is not cancelled when you're approved for the B1/B2. Although one can hold two different categories of non-immigrant visas at the same time, some consular officers mistakenly cancel one non-immigrant visa without prejudice when they give you another.
Am I asking too much or this is possible without getting denied at the
border in SF?
You can do so. The visitors visa B1/B2 and F visas are both non-immigrant visas which require demonstration from the applicant that they lack immigrant intent. The point you have to note is that your B1/B2 application will be viewed as a new application on it's own merits and the onus will be on you to prove you will leave the USA.
At this point, with having done part of your degree in the USA with you returning for completion, it is abundantly evident that your F visa has very strong, maybe overwhelming chance of success. Your B1/B2 application does not have anywhere near such a strong profile.
Bear that in mind, and that a refusal for B1/B2 will be a negative on your immigration history when it comes time to apply for F. It is however not a fatal situation because I was in the same position nineteen years ago, i.e refusal of B1/B2 and subsequent approval of F1 in a short time.
Also I think I'm eligible for Visa Waiver Program. Does that work
instead of a B2
The same reasoning applies as with the visa. Particularly because you plan to travel outside the USA before returning with an F1 (and not change status from within the USA which would have been problematic), this is also fine.
In both cases you ought to have a strong reason why you want to return to the USA. Overall I would say you have a pretty good case because if not for your exchange break, you would have been in the USA under the F1 without problem. SEVIS technicalities are the only reason you had to break your F1 tenure. Have a backup plan in the unlikely scenario Canada refuses you entry and also remember to request the border agent to admit you in F1 status when returning from Canada otherwise you may be readmitted as a typical visitor who briefly went to Canada and is returning to continue his 90 day VWP stay or 6 month B1/B2 stay.