Blooms look like they will start pretty soon. As best as I can tell it will be a white or very muted color due to cool and dark conditions. You may have some spider mite issues which should be addressed. Lots of people use bayer 3 in 1 or neem oil to treat.

Why do the leaves in the center look so flimsy? Is that because of the spider mites?

What could be a possible growth pattern for the new branches for next year? Any pictures of something similar?

There could be several reasons for the leaves looking the way they do. The most likely reason is spider mites. There are other possible reasons but I recommend starting with that.

The start of new branches should by this point be visible at the bottom of the inflo stalk. You should see a cluster of leaf tips for each branch which is forming. Hopefully you will have at least two tips forming which will in time grow further into branches. Sorry but this is the best image I have available right now.

So there are three little tiny growth tips but one, the smallest does not seem to have any leaves.