If works now, of course you can add new recipes, just do not forget the autoValue ;-)
(newly added recipes might even work with loaded savegame, but I cannot guarantee that)
A problem might be to find out the required keywords.
You can look into the existing extended crafting file, it already contains tons of new recipes. When I quickly read over it, I already found recipes for the creation of bracers, so a lot should be in already. You only need to find out, what is actually created and what is required to craft something. Most recipes will miss the 'autoValue' parameter and will thus not work out-of-the-box, but you know now how to make them work.
In my tests I found that having only the ItemCombos.txt file and no preview file seems to prevent a recipe from being added to the Recipes page of the crafting panel, but I think you could live with that, crafting the recipes in the experimenting window will still work.
