This is a very good idea. The more you can do this, the better and faster your work will be.
Have you ever made an action before? I wrote a simple tutorial here.
Also, some general info here.
And of course, this one will slice heaps of time off your output workflow.
2) When it comes down to technical basics, the files you're sending to the lab are just a bunch of ones and zeros. Simple binary data that comprises all digital files. The screen upon which you edited is completely irrelevant. All that matters is for your calibrated screen to show those ones and zeros the same as the lab printed them.
1) For the purposes of calibration, you must ignore those profiles. They'll become important later, but can only be utilised after you are confident with the calibration.
I have to leave now, for a little while.
Basically, I think your settings should be 300/300 (rather than 300/450) and High, or even Medium, not Maximum for the image quality.
No, no. Save the PDFs from the PSDs again, and take another look at this screen:
Can you take a screenshot of your screen, and show me? I need to see the settings you used.
Is this an accurate sum of the parts? I mean, the individual PDFs you merged to make this one - did they add up to 347-ish MB? Or has a whole lot of extra size been added in the merging process?
It's never a waste of time. I view every opportunity to remind people of the importance of in-camera achievements over post-processing achievements as a valuable use of time.