Thaumcraft is not really required for progressing through the midgame, but it is still recommmended that you try to progress it for a bit.
A few good goals to try and reach before you start the endgame:
 -Get a Primordial Pearl. For this you must get a lot of warp to unlock the Eldritch Tab.
 -Unlock the Ichor research. To check your progress on this, use /iskamiunlocked
 -Set up energized nodes for all aspects.