If your focus is on critical damage with or without terror, I would prioritise skills such as Redistribution. Before finding legendary class mods at lvl 50, I ran my entire first playthrough as Moze with a Marksman class mod which had +1 Redistribution, +1 Experimental Munitions and +3 Scorching RPMs. The Baby Boomer mod also can give +1 Redistribution as well as add points to Means of Destruction. These are viable mods to run with until you get your hands on a Blast Master COM (assuming you haven’t already.)
Having 2/1 Redistribution is an enormous help because it’s practically the same amount of ammo regen as +1 Redistribution and Forge combined, except you only need to spend 6 skill points and equip a suitable class mod to recreate the same effect. From there, you must decide what you want more: extra mag size from the BM tree, focus on splash damage via DW tree, or extra gun damage and shield tanking capability via the SoR tree.
If you’re looking to use a Blast Master COM then as an example, my build also uses one as well as places emphasis on scoring critical hits and boosting splash damage. But I also run with a Big Boom Blaster shield and a Deathless relic which is a less common but more eclectic choice of gear. This specific combo of gear means that you can take the unconventional and far less explored route of not needing to spend points on Means of Destruction or Vampyr, arguably two of the biggest reasons why people invest a lot into the DW tree in the first place, allowing you to spend points on other skills instead.