OK,these are my thoughts on fighting an a6m, yarbles.
On the merge go into a gentle climb, i.e. pull little more than 2 G's. Chances are he'll go into a tight turn and bleed off a lot of E. Watch his turn and during your climb, and turn gently away from his aircraft accordingly. This will force him to turn even further bleeding off more E. From here you can do a couple of things.
1) You can go vertical and attempt to rope the enemy if you believe you have acquired enough speed and height over the con.
2) maintain your spiral climb which will eventually put you above the a6m allowing you to control the fight.
3) Extend to a distance you feel comfortable with and reverse back into the con and repeat what i've written in the 1st paragraph. Remember, when reversing back into the con, be gentle. For instance, you could extend to 2k and perform gentle nose low turn to maintain speed for the merge so you you can zoom higher in the climb.
4) Run away- Not something i would choose to do myself, but it is an option so you can reengage later in a superior position.