Neither C nor V have any currently playable two letter words. A, with 28 two-letter combos has the most. M, with 12 two-letter combos, has the most amongst consonants. J, Q, and Z all come in with a lowly 1 each (JO, QI, and ZA).
In my opinion CH, (noun) the 4th letter of the Czech, Spanish, and Welch alphabets and (interjection) a sound made when trying to get the attention of another person, should be valid.
Also CO, which is a shortened for of "company" (no different than "biz" is a valid shortened form of "business") and is also the Gaelic word for "how" (hell, we already accept that the Gaelic "cwm" is a valid word for glacial valley, what's one more Gaelic word between friends?), should be valid.
As for V the only possible two letter combos are VA and VS. VA which is really the Spanish word for "go" or "will" is used in the phrase "VA VA VOOM", which is an onomatopoeia of a car revving. VS is the shorthand for "versus".
Then again in my fantasy dream world Zenga would add all the SOWPODS 2-letters words to the WWF list as well:
DI: (music) a tone in the ascending chromatic scale between do and re. C♯
EA: (archaic) river
EE: (Scottish) eye. (Interjection) showing revulsion.
FY: (archaic) Expressing disapproval.
GU: (Shetland) A kind of fiddle or violin played on the Shetland Islands.
IO: A moth, specifically the io moth.
JA: (chiefly South Africa, informal) yes
KO: (Japanese) Threat. Used in English in the game of Go, the ko rule prevents the repetition of a move.
KY: (dialectal and Scottish) plural form of cow
NY: (archaic) nigh.
OB: (historical) A halfpenny. (archaic) An objection. (genetics) The obese gene.
OO: (obsolete) The Greek letter omega. (ornithology) A Hawaiian honeyeater of the genus Moho (the Oahu oo Moho apicalis, Bishop's oo Moho bishopi, the Hawaii oo Moho nobilis, and the Kauai oo Moho braccatus), now all believed to be extinct.
OU: (ornithology) A probably extinct species of Hawaiian honeycreeper, Psittirostra psittacea.
PO: (obsolete) A peacock. (obsolete slang) A chamberpot. (slang) Poor.
ST: (interjection) Expressing a sudden desire for silence. (abbreviations) Saint. Street. State. Stone (unit of measuring weight). Store.
TE: (music) In solfège, the seventh note of a major scale, B♮
UG: (obsolete) To feel dread, loathing or disgust. (obsolete) To fear, feel horror; shudder with horror.
UR: (interjection) Expressing hesitation or inarticulacy; er, um. (informal, Internet, text messaging) your
YU: (archaeology) An ancient Chinese wine-bucket, often having a decorative cover.
ZO: (zoology) A male hybrid of a yak and a domesticated cow.
And most of all friggin' OZ: While it was a originally a place name, and thus a proper noun in L. Frank Baum's novels, and the various films and plays based on them, it has now morphed into general usage as a generic term for a mystical or fanciful place.