You'll be happy to know that I do have the custom shot/hit graphics written down on the GH2 to-do list. Actually, what I really want to do with the GH2 graphics engine is scrap the whole thing and find someone qualified to do it.
I've added the outdoors battle to the image list. I didn't add the size comparison chart yet- the Kojedo and Trailblazer should be smaller than they are, the Vadel should have the same shoulder height as the Jos, the Maanji and Radcliff should probably be bigger as well. The Maanji has a slightly larger frame than the Jos does.
I think I said somewhere that the average GH mecha should be 16m tall. That puts it roughly between Battletech (12m, originally) and Gundam (the RX-78-2 is 18m). This is a good height for Class 5 battroids. I'd go around 13m for the Trailblazer. Other mecha types, such as arachnoids and zoanoids, should be shorter but wider compared to battroids- I think the Kojedo would look good at 10m to 12m tall.