SB replied: The former is with regards to the poetry, the latter is with regards to the plays.

And, again, it's worth noting that De Vere being publicly acclaimed as a playwright explodes the argument that he needed to conceal his identity as a playwright.

SB replied: The Alternative Authorship theories, of whatever stripe, are the Nemesis of the more devout Stratfordians who've undoubtedly over-indulged their imagination, building up myths that positively begged to be torn down.

But however galling it obviously is to Alternative Authorship theorists - of whatever stripe - that William Shakespeare of Stratford-Upon-Avon was the author of the plays ascribed to him in the First Folio (with other plays having been lost, and some, like A Yorkshire Tragedy, tentatively ascribed to him) remains the overwhelming consensus. 

Yes, I think your summary of the categories of opinions pretty neatly summarises the respective positions regarding Shakespeare's authorship (or the authorship of "Shakespeare", as I suppose Alternative Authorship theorists would phrase it).

Your first point was the consensus for a long time.

Your second point, regarding the role of collaboration, is probably more widely accepted, apart from the most devout Stratfordians. It also knackers the argument that someone other than Will of Stratford-Upon-Avon collaborated on the plays that would end up bearing his name.

SB replied: And yet that Will of Stratford-Upon-Avon and the William Shakespeare who was stated to be the author of the plays in the First Folio were one and the same remains the consensus. 

And despite the sharpness of their intellect, the volumes of their evidence and the power of their arguments, Alternative Authorship theorists remain on the fringe.

It's true that we don't know exactly when any of the plays were written, and that isn't true only for Shakespeare, but for pretty much any dramatist of the period.  

But if The Tempest was first performed in 1611, Occam's Razor would seem to suggest that it was written around about the same time.

With Hamlet there are records of it being performed since the late 1580s, meaning that Shakespeare can't originally have written it if the established timeline is to be believed. The evidence here works against traditional dating of the play. 

SB replied: Hamlet isn't original to Shakespeare. It's an old myth which can be found in Saxo Grammaticus' Gesta Danorum (late 12th/early 13th century), and which had been translated into French by Francois de Belleforest in his Histoires Tragique (1570).

The 1580's Hamlet, often referred to as the "Ur-Hamlet", is sometimes attributed to Thomas Kyd, although some people think that a young Shakespeare may have had a hand in it, and some critics - notably Harold Bloom - arguing that it was an earlier version by him of the later, more mature work.

Mark Haslett wrote: Perhaps, but what does that say about Shakespeare's "Timon of Athens," "Coriolanus," and "All's Well That Ends Well"? These have no record of being performed at all before they appeared in the First Folio-- full 7 years after Shaksper of Stratford died.

SB replied: It's true that the dating of the plays isn't always agreed upon. We don't  always know when they were written, only when they were first performed - and sometimes not even the latter. But the inclusion of All's Well That Ends Well, Coriolanus and Timon Of Athens (and others) amongst the other plays attributed to Shakespeare in the First Folio and is strongly a point in their favour that they were written, or co-written, by him.