Missing Letters By Conto ( Crossword Centre )

[Matakari]

Missing Letters by Conto in the Crossword Centre

( For each clue, one apposite letter is absent from the wordplay. Clues are listed alphabetically by answer. Answers should be fitted into the numbered grid. Chambers Dictionary is recommended but does not give one commonly used entry.)

www.crossword.org.uk/missing.html

Good morning,
I’m trying my hand at a novelty for me, and would like some clarification of the preamble. I’m not sure if I understand it right.

For example:
A mature saying (5) : ADAGE ( To go in 7 A?)
Father nude…Nude? That’s a crime! (5) : THEFT ( To go in 13 A? )
One committed to assasinate the King in state capital of Eswatini (7) :MBABANE
( To go in 12 A?)

What are the “apposite letters absent” from these clues?
And must all answers be fitted wherever they can go in descending order?
Thanks in advance for your expert guidance!

[Neveracrossword]

Pomona, for 'How your..', think what an exasperated parent might say to a child's request. Your Go is correct.
The other long one starts with a T and also involves anagramming. It's basically just another word/phrase - think of Contacts in relation to mobile phones...

[pomona]

Thanks .. I have the GO ASK one now and telephone for 1st word of the other.....i'll start filling in a few on the grid now...