In the Radio Times for today, the synopsis for Robin Hood
has ". . .
Knighton Hall is razed to the ground . . ."

Nothing wrong with that as far as I can see.

The only thing I can find wrong with that is that they have
spelt 'rased' with a 'z'.

In the last decade or so it has become more common to use the
's' instead of the 'z' in words such as rased (both are
correct) to distinguish British English from American English,
the latter always use 'z'.

My elderly Chambers Dictionary, 1972 edition, has a full entry
for 'raze', with a cross reference for 'rase' simply saying
'same as raze'.

Would you write 'gase' or 'amase' or 'grase' or 'crase'?

Anne