Adding new keystroke combinations to TW editor?

[Jarred Jones]

Hi all. I am using TW for number of years now (~10), but strictly as a user and without knowledge how to change its features. I have numerous (~50) narow-subjects tiddlywikies, using them to collect bits and pieces of interesting articles, advices, etc from the web. I would like to understand how to extend some of existing features, but all my reading from the  web brought advices that  are to obscure for me to make any use of them.

(1) For example, I would like to add one more function to editing a tiddler, where one can already use CTRL+SHIFT+L to promote a current row into a bulleted list item, i.e.

  some text   -->   * the same text

I would like to add ability to equally easy get a double bullet (**), i.e. to add a new  keystroke combination that would instead do:

  some other text   -->   ** the same other text

Articles/discussions that I am finding on the web are all saying something like "add this to some kind of system tiddler ..." -  what? How would I do that? Do I need to load the whole tiddlywiki file to an text editor? What keyword should i search? Is there a place where all keystrokes are defined, where I would be able to insert/add the new keystroke?

(2) I keep images and other auxiliary files for each specific tiddlywiki in its own separate subfolder, e.g. for wiki  travel.html there is next to it a folder travel_files. Is there a way to set somewhere for that whole wiki a variable that I can involve with a keystroke, so that I can simplify setting up links to local images associated to that wiki. E.g. in an tiddler NYC i want to add a snippet of text and a link to a photo file travel_files/NYC23.jpg by manually typing

   [img[travel_files/NYC23.jpg]]

Desired dew function would be a simple keystroke that would drop in the body/text of edited tiddler following:

   [img[travel_files/]]

and I would only have to enter name of the specific image file to complete that link.

Is that possible? How?

(3) one more example would be missing search-replace ability when editing text of an tiddler. Currently, if I have anything more  that about 10 search-replaces to do, I copy the whole text to a text editor, do a wholesale search-replace there, and then paste changed text back into tiddlywiki. Is it possible to do search-replaces natively within the TW's editor?

Thank you for any pointers. Please be gentle, I am not a javascript coder, and am not familiar with libraries and frameworks used under the TW hood.