Well done Jazzgirl
I started after lunch only stopping to get the washing in and put away this morning's garden tools. So far I have nineteen or twenty. Usually at this stage I start putting the answers in the grid, but unfortuately, I haven't spotted the theme yet. I shall look again at those you suggested that I've got.
The grids aren't exactly designed to give an obvious lead-in apart from the two thirteens go in only one grid. I have got one of the 12s, but not the other and three out of four of the 11s.
I've spotted lots of references to religion, though I don't know the X saint.
I've checked out the Chambers page you've given, but can't see another name for a praying mantis there beginning with H that is 10,3. My googling has been in vain. But, I have learned a lot about them.
Apart from the generous hints you have already given, please can I have a hint for a couple to help me sort them out.
L2. My husband, who is musical wasn't able to help me out here.
M1.
Q1 and Q2
I'm assuming Chris isn't bothering with this one. But where is Brendan?