Sorry, before, I wasn't giving a comprehensive list of cuts. I was just pointing out a few that could safely be dropped. I think
Psychosis Crawler could stay if you want backup for Niv, but you're running a ton of counters and draw, so I'm not sure you need it.
I agree about the three card combo; you should never add cards that only do anything when you have another specific card (unless that card is your commander).
I would suggest adding
Flash, though, so that you can draw your deck with Niv, play LabMan at instant speed, then win the game with another Niv trigger. If they
stifle the trigger or counter
Flash, you can just discard to hand size and refill your deck with Ulamog.
Aside from that, I would suggest separating your cards into those you absolutely need and those that just seem cool, then start cutting the "cool" cards from highest cmc down. You could also cut those that are less useful or have worse value for cost, but that's a bit more tricky.