While I have many, many, many people try to HO me, I can't say that I really see it as a problem. Only about 1% of them actually hit me. I doubt I have more than 1 or 2 deaths per month from HO's, and those are generally when I'm knotted up in a many on 1 with several guys fighting over who's gonna get my scalp. Those guys obviously don't want a decent fight anyway, so who cares how they shoot you?
Number one rule when it comes to not getting shot- stay out of his gun solution. If you're getting HO'd, sure, the guy is a dweeb for taking the shot, but then again, so are you for giving him one.
If you think about it for a minute, what's the easiest HO shot to make from your perspective? Obviously straight on from the front. Any deviation from that makes it more difficult or impossible to hit. You don't need to do any fancy jinks or barrel rolls to avoid the HO, just don't attack him from the front.
If you're taking HO-type hits while merging, you just need to adjust your merge seperation. You can merge lower or higher than your opponent, or off to one side. The merge from a position lower than your opponent is obviously the safest, and leaves a lot of options. The common DA style merge where both planes pass nearly nose to nose works fine if both players agree to a guns-cold merge, but it relies on a "gentleman's rule" that doesn't (and IMO, shouldn't) exist in the MA's. I'm not saying I'll HO-shoot you if you try it with me in the MA, 'cause I won't, I'm just saying that if you present me with a shot, you SHOULD be shot. So, IMO, if you're taking hits from HO's, you SHOULD be, hehe! It's nice to see an opponent pass up an opportunity for an HO shot, but never assume he will.
The easiest option to avoid the HO and still do a "normal" merge, is to merge from the lower position. When approaching your opponent, dive down for speed, but make sure you go/stay lower than your opponent. Basically, try to fly UNDER him, not AT him. If he wants to HO you, he needs to fire while pushing forward on the stick, causing him to red-out and/or just plain being a very tough shot to make. Some guys can still hit you here, but if you just put your plane slightly over to one side or the other, it makes the shot even tougher. So, in essence, try to fly under one of his wings.
Now, ideally, start to bring your nose up as you get to within 2k or so from him. Aim for a spot about 2 plane lengths behind his tail. Still fly under him, but be on your way up into an immelmann. This does two things- makes his shot even tougher, and sets you into your reversal, while he's actively pushing forward for his shot, which is actually forcing him AWAY from his reversal. This is going to allow you to easily swing over the top behind him. If he tries an immelmann as he passes you, so much the better, you'll be given a nice shot straight into the top of his canopy.
I'm starting my dive 5k out or so, leveling out at 3k or so, and starting to come up under him at 2k, aiming to come up behind his tail.
I see lots of guys who try to HO me, they just so seldomly succeed that I don't see it as any big deal. There are a lot of options for merges, don't get stuck doing that DA style merge in the MA unless you want to be frustrated.
MtnMan