My interpretation of the clues. If you have 2 asterisks beside your
name, I need help.

FLABBERGASTED

John Masters
Les grabbed fat bananas and was extremely surprised (13)

Les grabbed fat*
bananas = anagrind
extremely surprised = def

Roy
Fat floater has terrible dates - surprised? (13)

Fat = Flab
floater = berg
terrible = anagrind
dates*
surprised? = def

------------------------------------
David
Gobsmacked daft gabbler fasted outside (13)

(f)gabbler*(asted)
daft = anagrind
Gobsmacked = def

------------------------------------
Duke
Shocked by play rabble staged with farcical opening (13)

play = anagrind
rabble staged (f)*arcical
Shocked = def

------------------------------------
**Mark
Shocked Southern knifeman changed sides, hid, got away (13)

Shocked = def
Southern = Fl (Florida)?
knifeman = stabber?
changed sides = anagrind?
unsure of rest

-----------------------------------
Luciano
Confounded spare tyre set badger flying (13)

Confounded = def
spare tyre = Flab
set badger*
flying = anagrind

-----------------------------------
Kevin
Surprised about Alfred and Bertrand having delightful experience in
the sack (13)

Surprised = def
about = anagrind
Alfred = alf
Bertrand = bert
delightful experience = gas
in the sack = bed

------------------------------------
**Bees
Refrained from eating frozen calf after testing facility is
overwhelmed (13)

Refrained from eating = fasted
frozen calf = berg ??
after = place indicater
testing facility = lab
overwhelmed = def

----------------------------------
Bonus clues

Duke
As if struck by lightning or exploded, blasted Faberge egg missing
(13)
As if struck by lightning = def
exploded = anagrind
blasted Faberg(-e)*
egg missing = indicator that letter e is missing from anagram

-------------------------------------
Bees
Grabbed at self clumsily and staggered (13)

Grabbed at self*
clumsily = anagrind
staggered = def

Bewildered gal stabbed ref violently (13)

Bewildered = def
gal stabbed ref*
violently = anagrind

"calf" = (ice)berg (please see http://dictionary.reference.com/browse/calf); icebergs are formed by "calving" from glaciers.

Bees

Oh, and only "refrained from" = "fasted"; "eating" is an inclusion indicator.

Bees

On behalf of Mark, if I may be so bold:  I'd assumed that "Southern knifeman" was "GA stabber" ("GA" = "Georgia"), "changed sides" indicates that "gastabber" becomes "abbergast", and "got away" = "fled"

Bees

B. Spollen:

Yes.  In other words, not a general anagram, but a swap of the
left and right sides.  As for what the resulting letters hid in,
well, they hid wherever they could find a place, which was inside
"fled".
--
Mark Brader, Toronto  |  ... "reasonable system" is of course defined as
m...@vex.net           |  "any one *I've* ever used..."   -- Steve Summit

My text in this article is in the public domain.

On Mar 8, 8:46 am, Rodders <roddymacpher...@yahoo.co.uk> wrote:

No, it's a reversal indicator. The complete cryptic working is:

about = reversal indicator
Alfred = ALF
ALF reversed = FLA
Bertrand = BERT
delightful experience = GAS
BERT "having" GAS = BER(GAS)T
the sack = BED
BERGAST in BED = B(BERGAST)ED
FLA + BBERGASTED = FLABBERGASTED

Kevin Wald  w...@math.uchicago.edu |  "Hwaet saegest thu,
http://www.math.uchicago.edu/~wald | yrthlingc?" -- AElfric

On Mar 8, 8:46 am, Rodders <roddymacpher...@yahoo.co.uk> wrote:

No, it's a reversal indicator. The complete cryptic working is:

about = reversal indicator
Alfred = ALF
ALF reversed = FLA
Bertrand = BERT
delightful experience = GAS
BERT "having" GAS = BER(GAS)T
the sack = BED
BERGAST in BED = B(BERGAST)ED
FLA + BBERGASTED = FLABBERGASTED

Kevin Wald  w...@math.uchicago.edu |  "Hwaet saegest thu,
http://www.math.uchicago.edu/~wald | yrthlingc?" -- AElfric

On Mar 9, 12:23 am, Kevin Wald <w...@math.uchicago.edu> wrote:

"Having GAS" is a delightful experience? Maybe "having a gas" could be
so interpreted.