@Adnan H.congrats on already being in the game!
Tough to answer this kind-of question, because it is so personal. Some people love the SFR game because they find it lower maintenance, others feel the opposite and rather everything under one roof. You can probably read literature on BP that will entertain you for days (if not longer) on this topic. The same can be said buying in B-class vs C-class properties, there are pros and cons to both.
Part of it will come down to the area you invest in, but the biggest factor is your personal one - what do you like best?
The only other comments I have relate to your pros and cons:
1. How difficult is it to find B-properties with the criteria you're looking for? If you'll be chasing unicorns and it's not really possible, then maybe this is not even an option. If it's something possible, then what is challenging about it? Will it take too long to find that your money is going to be sitting on the sidelines for too long, or will it take up too much of your time?
2. I'm not sure I really understand this point. When you say property won't appraise; are you referring to appraising to get all of your capital out, part of it, or it just won't appraise to what you're paying for it.
3. Also, not sure that I understand this point either. When you refer to refinancing and cash getting stuck, what do you mean by that? Because if you're looking at 5 or more units then you will need a commercial loan and you will almost for sure need to refinance down the line (likely in 5 - 10 years).
If you're looking to find a deal that you can refinance all your cash out within a short time period (1 year or less) and have your NOI cover your debt service then I think they are all good options, and it just again comes down to a personal decision. (If you want my personal preference assuming they are all good deals, it would be 1) apartment building, 2) B-class properties and 3) C-class SFR's.)
Best of luck!