An editor "must give reasons which shall cohere with all the bibliographical evidence both for the choice of the text upon which he founds his edition, where a choice is offered him, and for any textual changes which he admits into his text" (96). This is true, but if the editor stops at considering bibliographical evidence, they are going to do shallow work.
Greg believed that bibliographical scholars are editors should be two separate persons, the former investigating the facts of textual transmission, and the latter concerning themselves with creating critical editions based on those facts (97). So.... why didn't they stick to this plan? Or did the critical editors of the New Bibliography swallow the bibliographic narrative wholesale? Or did the bibliographers over-reach?
Once a given text is established as having more authority (i.e. being closer to the writer's manuscript) than another, that text should be chosen as the copy-text, and only emended or otherwise altered after careful consideration of Bibliographic evidence (102).
c.f. Percy Simpson's Shakespearean Punctuation (1911).
Elizabethan punctuation was more attentive to the pauses in spoken English than, as modern punctuation is, grammatical constructions in written English (107).
Hand D of Sir Thomas More, which is presumed to be Shakespeare, is only lightly punctuated, and given Moxon's direction that a corrector be 'very sagacious in Pointing' it is impossible to know how much the punctuation of a printed play book is the authors and how much the compositor's (108-109). Of course, an annotating reader might have also marked a text for punctuation before it was passed to a compositor (c.f. Massai).
While printshops tended to normalize spellings in-house, it is likely that a less-experienced compositor would have set his print direct from copy and without attempting to normalize, which creates a greater variation of spelling within a text (as in Q2 Hamlet) (109 - 111).
'While literary judgments are notoriously as shifting as the sand, bibliography provides a foundation of fact -- the rock of fact.' -- John Dover Wilson (qtd on 112).
Variations in the spelling of a characters name may be a sign of multiple compositors rather than authorial revision half-completed or multiple authors (113). You see that a lot in Merry Devil, I wonder what Wilson would say to the phenomenon of characters having the wrong names in the text (as opposed to speech prefix). I feel as if that is less likely to be a compositor error than an authorial one.
The best test for an emendation is that it is consistent with what is known or surmised of the textual history, agrees with the style of the author at the time of the writing, is the only probable reading that is appropriate to the context, and can explain the reason for the corruption (115).
Where it is supposed that a corruption in a printed text has arisen from a misreading of copy, it must be demonstrated that the manuscript words proposed could be mistaken for those printed, and the spelling falls within the range of variation witnessed in good quartos" (119-120). While some quartos may be better than others, I don't think any of them are necessarily bad.
New Bibliography has "profoundly changed editorial principle and practice. But no bibliographer would think for a moment of claiming that bibliography by itself is enough. To no aspect of Elizabethan literature, language, or life can an editor afford to be indifferent, and the ideal editor is at once bibliographer and critic, historian and antiquary, paleographer, philologist, philosopher, and theologian" (121). Where the New Bibliographers have failed is that, nowhere in that list appears anything approaching being a theatrical practitioner. Shakespeare was a man of the theatre, and while most writers for the stage were not, their customers were, and every producer must cater to the wants of their consumers.
New Bibliographers revolutionized the practice of editing, but for all their achievements, they neglected to look deeply enough into the one practice that was the sine qua non of Elizabethan playwrighting: the professional playhouses of early modern London. The narratives the New Bibliographers created neglect to account for the business of printing and playing, and the one fact that everyone who works in the entertainment industry knows: not all profits are necessarily immediate or monetary in nature.
Wilson, F.P. Shakespeare and the New Bibliography. Oxford: Oxford UP. 1970. Print.