What a nice, relaxing puzzle. +1, would solve again on my next coffee break.
Finished grid first:
Deductions used:
E is next to both D and L, so it can be placed.
R is next to E, and it needs to be able to reach the B in ROB, so the R is placed.
A is next to M, and it must have at least 4 unknown neighbours to house all of C,X,N and H. So the A is placed.
with CXNH around the A, ACQUIRE won't fit onto the three top rows anymore, so the C is placed.
Now WHAM places the H
AXLE disambiguates the N an X around the A
U must me adjacent to C, J and S, so it's placed.
ACQUIRE now places the Q and I
the T in JUST is now forced
P must be adjacent to both I and R, so it is placed
O in ROB is now forced
which in turn forces the V in derv (which is some sort of diesel vehicle, it seems)
the K in KEG has only one spot left
and even without using the remaining clue (FIR) we know the final empty spot must house the final missing letter, F.
Finally, as an improvement suggestion for the presentation: if you put the clue words to the right of the grid, and the alphabet below it (with the given letters already crossed out), it's much easier to work the puzzle, whether in printed form or in graphics software.
Here's what it might look like:
This image contains a puzzle that's made by user @international-dba, so it's not PD. OP can of course use it freely.
I couldn't get the pre-crossed-out letters look nice, so I left that thing out. Here's a link to the empty grid I drew for it with GD. As you can see, it's quite heavily aliased, but scaling it down will antialias it for you, so I couldn't be bothered to redo it properly. Feel free to use it in any way you like. (Whoever you are. All my own work here is PD by default.)