Haven't been able to fully solve this, but given that I'm leader of the current unit, I thought I should at least post my partial answer...
Skipping over the first paragraph (I'll come back to it at the end), the remainder on the text is:
constructed from cryptic clues (one per line).
Demeanour means imp's English name introduction.
MIEN - def: demeanour, M(e) I(mp's) E(nglish) N(ame)
Small film halves film cliche.
FICHE - def: small film, FI(lm) (cli)CHE
Fine qualities of ghost taken in by respiratory disease.
Had been victorious flipping present,
NOW - def: present, WON<
Win a goal: endless disdain with energy!
SCORE - def: win a goal, SCOR(-n) + E(nergy)
Second letter before Greek letter:
Awkwardly erect diamond left for bomb at that position,
Lure a little outside!
BAIT - def: bait, B(A)IT
Defrosts what's wrong,
THAWS - def: defrosts, WHAT'S*
A crystal season.
SALT - ddef: crystal + season
A yes heard! See?
EYE - def: see, sounds like "aye"
Odd six hearts for a retired element...
DI - def: retired element (Didymium), hearts of oDd sIx
SET - ddef
From odd drain, Origin writer,
DAN - def: Origin writer (Dan Brown), odd DrAiN
Yacht a girl!
CAT (maybe?) - ddef: catamaran + derogatory term for a female, though not really "a girl"...
Faint is constant within leave.
QUIET - def: faint, QUI(E)T
Alconja, leader of current unit!
A - def: current unit (Amperes), A(lconja)
Passing pale left chorus?
ELAPSING - def: passing, PALE< + SING
Guaranteed half of treasure!
SURE - def: guaranteed, (trea)SURE
That's all I know for sure, but given that
there's some pretty odd choices of words, there's clearly more going on. One observation is that the first paragraph is very oddly written, yet doesn't appear to be cryptic clues (and is also set apart). Within that paragraph, and the title, the are many apparently missing letters ("alway(s) look(s)", "ag(a)in an ol(d)", "For you, f(r)iend", etc). This makes me wonder if the answers to the critics can be made into something coherent be adding some letters...