Simplicity 8399 - AKA The great fitting time-suck

Behold, my newest sewing diversion from previous sewing diversions...

Last weekend I embarked on a muslin of this (apparently) simple blouse pattern, Simplicity 8399 from 1969 - not to be confused with Simplicity 8399 circa Kate and Leo...

Not that those dresses aren't lovely - it's just that they just don't fit well in my current career wardrobe. Actually, my current career wardrobe is almost non-existent, hence the sudden desire to sew a blouse. Unfortunately, Simplicity 8399 has been nothing short of a pain in the tuckus so far, and I'm blaming part of it on poor drafting.

First, there are the issues with the self-facing. The shirt front has a fold line to create the facing, but I am fully convinced it was placed in the wrong location. Here is the pattern piece:

The black line indicates the center front as marked on the original pattern. I'm assuming this is the center front anyway, since that's where the buttonholes are marked (which I attempted to demonstrate with my crooked little dashes). The fold line on the original pattern is marked in blue. When I followed these markings, however, I had trouble getting the blouse to overlap properly in front. So I re-examined the pattern and saw that the fold line is actually positioned at the real center front, right at the center of the neckline curve. You can see this a little better in this photo:

So I had to move the fold line for the facing over by 3/4", or else there wasn't enough fabric for an overlap to form a placket. Once I did, everything lined up much better. I also had to adjust the curve on the neckline edge of the self-facing, to compensate for this change.

The next problem I encountered was easing the sleeve in. I measured, and the sleeve cap is 2" longer than the armhole measurement, which falls on the upper end of suggested ease, according to the venerable authorities at Sewing.PatternReview. So that will need to be shaved down. Even so, the sleeve is not a good fit on me. It fits fine with my arms at my sides...

But when I lift my arms, I feel quite restricted, especially reaching toward the front...

Here is how it looks from the back...

Pardon the photo overload, but I wanted to show how the strain lines on the back dramatically increase as I move my arm forward. I know some wrinkling is natural, but this seems over the top and feels very uncomfortable. I'm sure if I made this up in the delicate voile I have in mind, it would tear in no time. So what's the issue? I can think of a couple things. First, I need a little more ease across the upper back. You can see in these photos that I removed about 2" of the width from the front and back by putting in princess seams (1" removed at each). I won't keep those as princess seams in the final garment - I'll just slash and overlap the pattern pieces like you normally do when you grade a pattern. The pattern is for a 38" bust, and I am closer to 36" so this adjustment seems logical enough. But I might have been over-zealous in removing a whole 2", and I might need to add some of that back in to make the upper back fit better. This will help a little with the strain I feel when moving my arms forward. But I still think some of the problem is in the sleeve itself. The armhole isn't too low - I've encountered that enough times to recognize it. It's as though the width across the upper sleeve is too narrow. Or maybe the sleeve is sewn on at too steep an angle? At any rate, I'm waffling between starting over with a different blouse pattern, or sticking it out and finding a way to make this work. What would you do?