Rich, glad to hear you're finally taking up the challenge of flying something other than bombers. It will give you a whole new perspective on the game and the discussions on the BBs.
As to HO avoidance, if you dont intend to stick around and fight the guy, a simple nose down manouver or barrel role is often enough to throw off his shot. You fly through and, since he has to reverse 180, you're gone by the time he does.
If you plan on fighting think of it in these terms; If you both fly straight at each other (or close to it), you aren't setting up to aquire his six. You can't. At best, after the merge, if you both turn (immel, etc.), you're probably going to end up facing one another nose to nose again. And the cycle continues until someone breaks it (probably to their detriment), extends or wins a HO or high forward deflection shot.
So, to avoid this, you need to create seperation (vertical or horizontal) so that your already turning for his six as you merge. That might mean you have to turn out, briefly showing your belly but that's ok if the timing is right. Roll out, then back in, or dive and pull back up. Either way he'll have to turn into you and the fight begins. At least you're past the HO and now it's time to use your acm to gain angles. There is still the possibility of a high deflection forward shot on the merge but you'll just have to learn what that looks like, and the angles needed to avoid it (or take it).