Solution to 6D has been deliberately left unsolved and is to be answered only by a non-regular / novice commenter, with proper annotation. Those who have answered earlier in the week, please give others a chance.
Open for anyone to answer, if not solved by 1 PM.
ACROSS
8 Hood's whiskey consumed by military officer (4) COWL {CO{W}L}
9 People who turn up at programmes and people who look after them (10) ATTENDANTS [DD]
10 End silly war with little dog (4,2) WRAP UP {WAR*}{PUP}
12 Bewitch portal (8) ENTRANCE [DD]
14 Now that chap starts to relay enamelled stick (6) ADHERE {AD}{HE}{Re..y}{En...d}
16 After 51, military policeman's droopy (4) LIMP {LI}{MP}
17 Snap short bread with king (5) BREAK {BREAd}{K}
18 Assist in satchel preparation (4) HELP {T]
19 Commander in chief captures the French Resistance clergyman (6) CLERIC {C{LE}{R}IC}
21 No surety is required to be arranged for contests (8) TOURNEYS*
23 Wrongly aid flier to get a place to take off, perhaps (8) AIRFIELD*
27 Endlessly Cortes' travels amid undulating dunes alone (10) UNESCORTED {CORTEs} in {DUNES}*
28 Looks at frozen water, I hear (4) EYES (~ice)
DOWN
1 Copious rot arose before latrine renovation (10) TORRENTIAL {ROT<=}{LATRINE*}
2 Applaud and reject part? Nonsense! (8) CLAPTRAP {CLAP}{{PART<=}
3 A member of parliament in room for relaxation is wet (6) DAMPEN {D{A}{MP}EN}
4 Notice centre of the ear (4) OTIC nOTICe
5 Retort and pans (4,4) SNAP BACK {PANS}<=
6 Aunt dancing in front of church may be this type of girl (6) ?A?T?H (Addendum - NAUTCH {AUNT*}{CH} - See comments)
7 Dish that's a little soupy and wet, in retrospect (4) STEW {So..y}{WET<=}
13 Choose delectable part (5) ELECT [T]
15 Rarely aces run in competitions where everyone, except the final ones, does not aim to reach the finish line (5,5) RELAY RACES*
17 Famous composer's role is changed for a single man (8) BACHELOR {BACH}{ROLE*}
18 Chinese guys chasing female accomplices (8) HENCHMEN {CH}{MEN}<=>{HEN}
20 Reject garbage (6) REFUSE [DD]
22 Learners leave unrestrainedly, disorganised and messy (6) UNTIDY UNresTraIneDlY
24 Hostelries in two directions (4) INNS {IN}{N}{S}
25 Some things to connect... (4) DOTS Rebus
Reference List
Whiskey = W, Now = AD, King = K, Commander in Chief = CIC, The in French = LE, Resistance = R, CHurch = CH, Chinese CH, Directions = N,S