The overall effect of the chaplain is successful I think. Solid colors and nice contrasts. I don't recall what your goal is, table top quality and done or continually learning and getting better. For tabletop quality you're right on. To improve, some of the details need to be handled differently.
I wouldn't recommend painting on the sprue. Invariably, this means that mold lines get missed and then there are the attachment points which don't have paint or primer on them once removed. I always paint marines in parts: head+chest+legs+base, left arm+weapon, right arm+weapon, backpack. This allows me to test fit everything before painting it, adjust the shoulder pads, line up weapons and hands, balance over the base. And I can clean up all the flash and mold lines.
When it comes to highlighting, it looks like you could also stand to thin your paints out more. This would have helped quite a bit on the edge highlights on the black parts of the armor. Right now they're too wide as well as rough/uneven.
Lastly any tips for painting the shoulder trim orange ofthe 6th company?
When working over a black base coat, the most important thing to remember is to build up layers of color to your highlights. With a white base coat hot ate essentially starting with the highlights and shading down. With a black base coat you are starting with the shadows and building up to the highlights. It's also worth considering that most miniature paints are translucent and not totally opaque.
When painting the orange trim over a black base coat you can do a few things. Paint a layer or two of white over the black and then paint the orange. Or you can layer up thin coats of brown, dark red, light red, and then orange. I prefer the second method and have used it extensively on my khornate armies. You can also do some combination as well.