Good topic: what to do if you don't' have much time to do a full class? First, let me offer some flows specifically addressing this topic. Check out the
"Yin Yoga Channel" on YouTube. Here you will find 30 minute flows that target the spine, legs and hips, plus a quickie: a 10 minute practice. There is always time for a Yin Yoga practice!
Now to the specific questions - first mam5262's question: Your flow seems perfectly fine to me. You don't always need to do a counterpose that last as long as the original posture. Your flow has more flexion than extension, and that is quite alright because you do have some extension after the flexion. The real key though is - how do you feel after the practice? Do you feel balanced? No pain? If you feel good, then it is working!
Re Aleksandar's flows: again, it all depends on how you feel and your own experience and abilities. For many people, going from Butterfly (flexion) to a very deep backbend in Camel would be way too much of a change of direction: I would recommend Sphinx or Seal before trying Camel. But! If you are a naturally very flexible person and find Camel super easy, this may work for you. I would not teach it this way in a general, all-levels class though. Personally, I like to reserve Reclining Twists for the end of the practice because twisting is such a nice way to restore the spine and nervous system back to a more neutral condition. However, ending with Knee to Chest could be a nice ending too.
For the B series: I would perhaps move the Saddle up earlier. Since you woke up the spine for extension in Sphinx pose, it is ready for the more challenging stress of Saddle; why not put them together, with a short Child's Pose in between?
Cheers
Bernie