Quick Cryptic 1047 by Teazel

First of all, apologies for the supremely sparse blog - it's the result of work troubles, technical failure, and last-minuteness. I found the puzzle hard, possibly due to the aforementioned stresses, or just having an off day. I'm still not sure I've fully understood 4ac or 8ac. Hopefully I can explain my parsings on this dreadful iPad. I realise this is not at all helpful, especially for beginners, but it's the best I can do; please ask if stuck.


ACROSS
1 BUNK - double definition.
4 HESITATE - double definition, pause/what you might do if lost.
8 I DECLARE - double definition, a phrase introducing a statement/cricketing term.
9 RIFT - FIR (pine tree) backwards (falls back) and last letter (rear) of foresT.
10 BEHOLD - EH (what?) inside (captured by) BOLD (daring).
11 TROWEL - first letter of (initially) Received, inside (wrapped in) TOWEL (cloth).
12 TAKE A BACK SEAT - double cryptic definitions.
16 ASTHMA - cryptic definition.
17 FASTEN - F (female), A and STEN (gun).
19 TYPE - outside letters of (extremely) TrickY and PE (exercise).
20 GRATEFUL - cryptic definition, a 'grate full' could be a small delivery of coal.
21 CRUSADER - anagram of (horribly) SCARED, around RU (rugby union, sport).
22 LIPS - all but the last letter of (almost) SPILl, reversed (over).

DOWN
2 UNDUE - UN (peacekeeping force) and DUE (expected).
3 KICK ONES HEELS - anagram of (dreadful) LIKE SONS CHEEK.
4 HOARD - O (love) in HARD (difficult).
5 SCEPTIC - SEPTIC (infected) surrounding (filled with) C (cold).
6 TORTOISESHELL - double definition.
7 TAFFETA - F (force) and FE (iron) in TA-TA (so long).
10 BIT - double definition.
13 ASSAYER - AS (like) and SAYER (speaker).
14 BLAGGED - BAGGED (claimed) surrounding (to hold) L (pounds).
15 TON - reversal of (over) NOT.
17 FLAIR - homophone of (we hear) "flare" (to blaze up).
18 EQUIP - QUIP (joke) and last letter (end) of programmE.