EDIT: AUGH! My blogging software screwed up on me and no one told me? Geez you guys. So if you're confused, here it is. WITH TEXT THIS TIME.
Ok, I actually did this picture up some time ago, but never got around to posting it up. So here it is! :)
A: DE has the advantage of being able to grab either gem tile in 3AP starting from a dead stop. So abuse this! If you opponent ever leaves his gem tile open, that's your cue. Pop a VM, grab that tile and abuse his gems like they were red headed stepchildren. On the flip side, THIS IS THE TRIBE MAP. Do NOT leave your gem tile unoccupied! Or you'll be the one waking up with a sore bum in the morning.
B: Imps are kinda boring most of the time, but on this map they are good for 1 thing. Or 2 things, they are pretty boss at killing gems. But yes, you can pull your opponent's gem tile guard off, move the imp onto the recently vacated gem tile, and hit that gem for x2 gem bonus damage (you did keep your own gem tile occupied, right?) This is pretty much a sacrifice of the imp, but it's practically a forced move for your opponent, because if he doesn't take care of that imp, he is definitely going to LOSE that crystal.
C: Usually, the corners of the map aren't very useful, and you never want to have any units in those corners because those units will never become useful where they are. But on this map, priestesses can be surprisingly useful in the corner! They can heal/rez whoever is on the helm/gem tile, and reach the other helm/gem tile by spending 1AP to move forward. Plus, the gem protects the priestess. This is especially good because there's so little usable space near the deploy tile - the attacking units are better placed forward. I guess this works for engineers too - you can bubble the helm/gem tile.
D: This is a good spot for those 3 range units (like the necro), but not because of the usual reason that it's a sword tile and necros are good with sword tiles. Necroturrets don't really work too well because the area that the necroturret covers isn't really important at all. You can't hit the gem tiles, you can't hit the crystal, you can't even hit many positions from which people can hit your gem! But you can however do a peekaboo - ready to move out from behind the gem and hit your opponent's middle crystal for major damage any time you control 1 or both gem tiles. The other big thing is that it blocks your sword tile. That sword tile is more dangerous to you than helpful for you. Like I said, even a necro on that tile can't hit much of anything interesting, much less an imp. On the other hand, the lack of space means that your stuff is usually clumped around the deploy tile, and in particular around the sword tile. A VM or chief can run in, take the sword tile and ruin your life. So you have to leave something there, and it may as well be a necro.
E: This is where most of your stuff is clumped up. This is also where, if you have units, grenadiers, gunners, wizards, witches, rocket dwarfs can splash your crystals and your units at the same time. This is bad, because you're pretty much forced to heal up and ignore the splash, or trade for the grenadier or whatever and eat the crystal damage or any other splash. On the other hand, it's really really hard to avoid having units in this area, so you're going to have to balance leaving units there and risking splash, or spending the AP to move off.