Thanks for your quick answer.
"Too much effort" for you. Sure, I understand it.
e) what I ask you is to be able to customize the list of that button
And, yes, I'm aware for snippets. These are good tools. But, unless I'm wrong, snippets are not able to surround some selected text, ie to insert some text1 before selected text, and some text2 after it. Often, I don't have to create code, but I have to modify it, so I select words before modifying around it.
About my first wish, to extend selection between imbricated tags recursively from inside to outside, I make a simpler request : instead of that, I'd wish to be able to select all the text (including any tags inside) between selected tag and the paired tag (supposing cursor is anywhere in some tag, between < and >). Of course there would be the matching hotkey

It would be almost like current Ctrl-Alt-T, but instead of between >..<, between <tag>..</tag>
Best regards