Ever since I found a Blast Master COM, I dropped my Bloodletter COM for it and that was before the Bloodletter got nerfed. If you’ve already got a skill point in Redistribution, then you’d be surprised how much of a DPS buff it is in itself when you’ve got 2/1 in that skill, not including the passive bonus for guns (and grenades) dealing splash damage as long as you don’t reload.
Your build in terms of skill points looks very similar to mine too; although my Blast Master COM has +2 in Vampyr, it never is a factor because of the Deathless relic (and no Bloodletter COM to convert the health regen) so it’s totally doable if you’re looking to maintain that ‘no Vampyr’ angle. You might lose out on the utility of the Bloodletter being your sole means of investment in Phalanx Doctrine, but you’re wearing a Transformer shield anyway so you should be fine.
However, the one weapon that will lose out on DPS if you change to the Blast Master is the Foursum due to its low-ish mag size and how often you reload with it. But the Trevonator and Westergun (both of which I also use in my build) will dish out way more splash damage thanks to 2/1 Redistribution, and you can use the Scourge without reloading if you synchronise your blasts with Cloud of Lead.