Question for OP: what are you trying to do with your phantom, open class or stock class?
The pump stroke will smoothen with usage. The key is to use a *light* amount of oil and to clean it after each use. This will allow for a natural break in of the metal parts, while also clearing out the debris that form in the gun as part of that break in process. You might look into "Outlast." Many people swear by this stuff, and I myself was shocked at how much better is was than gold cup oil, in terms of not evaporating, not developing the gunk, and staying slick.
CCI's dual rod undercocking kit is great, but I still think the best pump stroke is with the plain pump handle that goes over the barrel. The key with smoothness is avoiding binding - I recommend keeping the return spring on the pump rod because it seems to help keep everything in line. Another key here is to pick up one of the pump rod shims. This takes a ton of the play out of the pump handle, which again, helps prevent binding.
As far as the trigger is concerned, I know there are some people who've done mods but IMO it's not necessary and here's why. The reason why I asked that question at the beginning is I've tried every conceivable configuration with my phantom, which I've used in games against a mix of everything from rentals to high-end electros. At least 90% of the time, I find myself falling back to the same strategy no matter what setup I'm using: taking it one shot at a time using lots of snap shots and focusing on positioning. The difference between 1bps vs 2bps when going against mechs and electros is negligible and usually my efforts are better spent concealing my position or moving to a new position rather then trying to fit in another shot before the tornado of returning fire is hurled my way. You will never win a gun fight with a phantom.
So in my perspective, all roads lead back to stock class because you don't really gain that much in terms of firepower with an open class phantom. Once you embrace stock class, these negatives of the phantom don't really matter as much (but def do the things I mentioned and pump stroke will improve). Running stock class with a phantom plays to this gun's strengths, that is light weight, mobility, and some would say accuracy (mostly due to ergonomic factors).
So I would say if you want to shoot fast or shoot a lot of paint in one session, go with your cocker or sterling. In my opinion I don't really see the point in trying to shoot a pump real fast so I would prefer to just go to a mech gun, but to each his own. If you want light weight and the challenge/thrill of stock class, play your phantom - your pump stroke will get a lot better over time.