Looks pretty good for a first holster. From what I can see, you've pretty well spotted your own areas of improvement. Other 'little details': It's kinda hard to see from the angle of the pictures, but pay attention to where the sweat shield is in relation to the slide. If you have a good frame safety, there will be little problem with the holster deactivating it- still, it's something to pay attention to. Also, where the sweat shield meets the body of the holster, I've found it best to trim it a little (before stitching) to ensure that there's nothing there that could contact the mag release. Just a little cut out of the leather, blended with the lines. On the front of the holster- again, it might just be the angle of the photo- be sure that you can get a full firing grip on Ol' Loudmouth there, while it's still in the holster. It looks like the leather under the trigger guard may be carried a little higher than it should be. On your belt slots- They look a little wider than you might need (unless you're wearing a double layer belt) and that could cause some instability by allowing the holster to move on the belt. The easiest way to do the slots if you don't have a large bag punch (slot maker) is to use a standard punch at each end of the slot, then connect the holes with a chisel of the correct width.
For your boning of the leather, instead of relying solely on modeling tools, styluses, etc., try rolling over the majority of the frame/slide with a rolling pin. That should help compress the leather enough for you to 'get the lines'. For the finish on the holster, you do need to pay attention to the edges. Even if you don't have an edger, you can lightly sand the edges to remove the corners. From there, dress the edges per Bob Park's (aka Hidepounder) tutorial. It can be found in the "How do I do that" section. You may not have all the tools, but you can substitute with what you have. In place of a rotary burnishing tool, some scrap denim from an old pair of jeans works very well. (It just takes a bit more time and a lot of elbow grease)