[MD_Titus]

you missed hitting the radar, thus leaving the massive 321s open to interception.

did they have gigants in 1940?

this was in fact the thing about the battle, the only time the luftwaffe actually kicked a hole in the radar net was a chance raid by epgrp 210, which took out a generator. however the luftwaffe never realised what they did, and utterly failed to exploit it.

drop tanks would have allowed the fighters more time over london, but that was at a stage when the battle was already shifting in the UK's favour - hitting london took the pressure off the airfields. a fair chunk of those hit had in fact not been active fighter command fields, but the pressure was off the ones that were. it would have allowed the fighters to cover the bombers for longer, but they would've been stripped away by the methods park used (and which 8th airforce would face over europe later in the war), in that he sent many smaller formations to intercept bombers along the course of their ingress and egress. this also relates to the myth of the big wing's success and how it was not the way to deal with the battle of britain.

so, stages 1 and 2 of your plan are what they tried to do, although they didn't know about the shadow spit factory elsewhere in the country and only hit southampton iirc.

simply carrying out the plan they had, but actually targeting only active fighter command fields and radar stations, as well as aircraft factories, and not being goaded into bombing london. that could have gained them the ability to surprise RAF fighters on the deck more often, get raids in and hit targets without being intercepted as effectively, and possibly led to local air superiority over the south coast of england, idea being that fighter command pulls out of the most affected airfields. then sending paratroops to capture the southern bases that have been bombed out of use, and resupplying the landing force that way... that could've ended badly.

it relies on intelligence the germans didn't have on quite what chainhome was and how it could be knocked out - not hitting the masts themselves, but going for buildings around them