Looking at the photos I think there are a couple things happening here which makes the thighs look off a bit.
1. Freedom of movement is a great thing when walking and it looks like you can bend your knees quite well. But I think the thighs are sitting up a bit too high. You should drop them down a bit and reduce the gape between the top of the shins and the bottom of the thighs. Looking at reference pics from the movie, there are some troopers that have a large gap but most have a smaller one. This will also bring the top of the thighs down so they aren't up under your cod plate.
2. A right side photo shows a lot of slack in your but piece and it appears to be popping out beyond your kidney. If you shorten the strap that connects it to the cod, you can tighten it up and reduce that gap. You may have to trim the sides of this under piece if it's rubbing against your thighs. I had to.
3. Once the but is in position, take another look or photos. I'd leave at least a 1/2" gap between the top of the thighs and the cod. This will improve the look and reduce any clicking when you walk. Do the same at the back of the thighs. Start trimming the front around the cod, cut the top of the thighs and the inner thighs to make the gap. Remember to leave a bit of material for a new return edge, especially on the front. I would do a return on the inner sides too, don't want that area to be sharp. Also, I think seeing the black gap around and in between the pieces is important to the look of the finished armor, just don't over do it.
4. When you've sorted out the front, put it all on and review again. You'll want to trim the top of the back of the thighs around the but plate. I did this but later realized I also needed to trim some off the but piece too. There was just too much extra material there, especially on the sides where it touched the thighs. Again leave some material for a new return edge. Look on my build on page 5 about 1/4 of the way down. You'll see how I trimmed the back.
Here you can see how the thigh is down tighter to the shins.
Here you can see the clearance around the butt plate.
Keep up the great work. It's these final stages where you spend much of the time finessing the pieces and fit.