Howdy!
Ok, lets take your questions one at a time...
From what you are telling me the red gun is out of line horizontally resulting in the red scan being bigger than the blue or the green. (The purple test pattern should make this fairly obvious). It usually results from the deflection yoke being off center, as we already discussed, but it can also result from some graphics boards that force you to adjust the horizontal centering too far off the middle position. If you have image positioning capability on your video card's drivers, try putting the monitor's horizontal position at center and adjusting the card to compensate. Someplace between adjusting the Card and the Monitor, you may find a spot that minimizes this error. It works sometimes, when the error is minor, but not always in the case of severe errors.
For the colour balance issue... First set the black level as I described --so you can see the inner circle but not the outer one-- then bring up the RGBhigh image. If your video card software has colour adjustment, turn it off. (This should be used only when your monitor doesn't have it) Next go into your monitor's onscreen menu colour adjustments, set them for manual or user adjustment so you can manually tinker with the balances. Individually adjust the red green and blue levels until they display with equal brightness on your screen. Being the picky soul that I am, I tape a piece of white paper to the side of the screen and use it as a "white reference"... stare at the white for a few seconds to "calibrate" your eye and then look at the test pattern. Any variances in brightness between red, green and blue should become fairly obvious. When done correctly the whites should look like paper.
For rendering purposes the goal is to have a monitor that is as colour neutral as possible. Others will see slightly different versions of your work, depending on the adjustment of their monitors but there is nothing you can do about that. As far as I know, there is no published standard for this.
Don't worry about the rgb plugs they're signal inputs that can be used with some high end DVD players and in broadcast or security applications. It's unlikely you will ever use them in computer applications.
As for the question of whether you should call Philips again... Frankly, I'd be terrorizing them by now. An unacceptable product is an unacceptable product, no matter what their specifications say!
I guess I'm lucky, having worked with this stuff so much. I have a KDS VS7I that I am in love with. I bought it knowing full well that I was going to void the warranty on day 1. I took the monitor all apart, painted the case black (I HATE white monitors), re-seated the deflection yoke, installed magnetic correctors, adjusted the convergence, fixed a suspect connection in the horizontal output and then reassembled everything. It's been a joy to work with for 3 years now... but even with all I did there is still a minor convergence error in the lower right corner I couldn't correct. My point is that there is no such thing as a perfect monitor... some things you just gotta ignore.
If you want the ultimate in display accuracy, you're going to need to get into LCD flatpanels. These monitors, by their nature, have no issues with focus, convergence or linearity. Since the colours are produced by fixed location cells in the LCD array, these things can never change or get out of tolerance as they do when you are counting on a magnetic aiming system to land an electron stream within .2mm of the right place, 7" away.
Have you considered getting a refund and going LCD? Most of my customers and friends have them now, NEC seems the best, but just about any LCD with decent response time is going to be better focused and more linear than a CRT based monitor.
In any event... Let me know how you make out!
<b>(</b>It ain't better if it don't work.<b>)</b>