Not addressing the shirring because I've never seen anyone do it well and I guess I just don't "get" the artistic vision (or whatever) behind it. But a couple of thoughts here:
1. As others have said, you just have to expect that your first shirt won't be exactly right.
2. The amount of slope in your shoulders is really unusual. It seems to approach 45 degrees, which is not something a shirt maker is going to automatically account for. This explains those folds in the front shoulder area.
3. You need to look at these photos of the first not-great shirt not as a failure on anyone's part, but as a necessary step in the process. This is how it works -- you take your best shot as a starting point, gauge the results, make adjustments, and go again.