With the part about what if the Luftwaffe had A6ms I think you will find a wide range of opinions on weather that would materially affect the outcome of the BOB here.
For whatever its worth I tend to be of the opinion that while unlikely to change the ultamit outcome for a variety of reasons, ssome related to air power and some not, it would have made things much tougher for the Brits if for no other reason than time on station. If each hypothetical German A6m can spend half an our or more fighting over Britain insead of 5 or 10 minutes as was often the case with the Bf109 that is a huge force multiplier independent of the realative merits of the two aircraft.
Staying over British territory for an extra 30 minutes means the RAF has 30 more minutes to also attack you, or flying deeper into Britain brings you into range of more fighter groups and also allows the coastal groups to land rearm and refuel and bounce you on the way back out. Staying over enemy airspace controlled by an efficient integrated air defence network for longer than necessary is probably not the greatest idea, and lets not forget both the Luftwaffe and RAF loaded their planes with armour and self sealing tanks after analyzing their losses during the battle of France, the A6M had neither, and you wouldn't be facing worn out MkV's but new build Mk1/11's.