Just watched the Search and Destroy game and I think you've got the right idea about editing.
The footage largely speaks for itself but you've added text to clarify things, that's good. Videos aren't worth watching if it's not made clear what's going on. One thing I would say to change, is to add some sort of outline to the text, if it goes against anything the same colour as it, it's going to turn invisible and be unreadable. Not such an issue in that video, but at points you might struggle to position the text so it's always visible without an outline.
I think having that water case on the camera ruins the sound quality, which I personally rate pretty highly. I'm not sure what the sound capture would be like without it, but if it were me I'd protect the camera some other way so as not to impair the sound. Or add some music to the videos to help up the atmosphere, to distract from how quiet the game is. Or perhaps the drift can have an external mic or something? I'm not sure.
I use perspex discs for the camera lens, and thankfully the Contour doesn't have a screen or anything on it anywhere else, you could probably throw it down some concrete stairs and it'd be alright.
I think going in and out a lot, from bright to dark, screws with the camera quite a bit too, it's insanely hard to see anything at the start, or whenever you're looking into the sun. Not a lot you can really do about it though, I guess. One way to help it though, is to angle the camera downwards slightly, so that you're less likely to get sun light shining directly on the lens, as that's what causes the white/blackouts.
Might be worth fiddling with the exposure settings to make it easier to see when the picture darkens, though there's not a lot you can do about white-outs, they happen most when you're looking from a dark place into a light one, so if you want to get the footage to be the best it can, you'll have to decide whether to just play as you normally would, for yourself, or play for the best video you can; which will require you to look at things longer than you usually would and hold your head in certain places, at certain angles, to best make use of the light available.
I have a pretty slow paced, defensive play style, so it tends to sort itself out for me a fair bit, but on games with lots of moving inside and out, I try to sit back from windows, but focus on looking at them to give the camera time to adjust to see what's outside. Flicking back and forth inside the buildings tends to just leave the windows looking like white squares.
I'll give you a sub though, see how things develop.
The site you're at looks pretty badass by the way.
I completely agree with everything you have said and I'm definitely going to try that camera trick you mentioned by angling it lower 
