I personally believe the process is convoluted when “how I look” and “how I feel” are intertwined. The latter is critical, the former is distracting. Though of course there are some things which are to be noted in the physical appearance. In the larger picture however yoga (or in this post’s case, asana) isn’t intended for the external body.
One of the issues raised is how does another “physical” practice assist a human being who leads a very physical life? When a person who is incredibly active, lives most of their life in a physical way (only) another physical (only) practice is like shooting lighter fluid on burning charcoal briquettes.
As a teacher (of yoga) I also have concern with the paradigm of “if it feels good, do it”. For most people that could be defined as staying in bed all day, eating ice cream, and drinking a bottle of booze. And of course we know that isn’t particular “good” for us. So there has to be a separation between what tastes good and what is good for us. Does this asana practice “taste good” or is it actually balancing relative to your living?
More to your question…
when muscle soreness is frequent rather than occasional (and based on using that which has not been regularly used) AND that soreness is not in the belly of the muscle but rather near the attachments, the work has either been too much or it has been done improperly. In both cases the secondary support structures (connective tissue) have been enlisted and that is a sign to make a change.
There’s nothing wrong with some free-weight use when it serves you and is done with integrity.