Yes, with no choke it will take a good 5-10 minutes of warm up time before you go anywhere. I have a bronco with a turbo that is carb'd and I had to mill off the choke, so I know how you feel at start-up and letting it warm up for a while. It will "load up" as you say until the engine comes up to operating temps.
How are your fuel filters? I run a filter before the pump and one after the pump.
Where do you have the electric pump located, hopefully closer to the tank
the better. The electric pump makes a better pusher of the fuel than a puller for the fuel.
Do you have it on a relay? If it is mounted back by the tank, you will need a relay to keep up with the voltage demands due to the long wire run via voltage drop. And make sure the supply voltage is directly from the battery.
Make for sure that you have a very good ground to the pump, I have seen people chase fuel related problems for months and it only ended up being a bad ground/connection. You can never have too much ground, I run a cable from the neg. side of the battery to the block, from the block to the frame, and from the frame to the body.
You could always go back to a mechnical pump, just to check and see if it is your electric pump.
One last question, the carb is new, yes? Or rebuilt? If not maybe it is time for a rebuild of the carb itself.
Let us know.
Kirk