Like the titel states I miss a few examples for each possible Crafttweaker methode.

Would be niche, if you could give a foew to each of the "adds" methode :)

Done. The crafttweaker wiki should also be helpful. It won't explain the Rustic compat, but understanding the basics will be helpful regardless.

So is it not possible to have the second input of the normal condenser be nothing then?
This line returns errors and adding brackets around null only creates a valid recipe for the advanced condenser. Angle brackets around null also give errors.
mods.rustic.Condenser.addRecipe(<rockhounding_surface:aging_items>, <rockhounding_surface:gypsum_items:4>, null);

The ItemStack page of the CraftTweaker wiki doesn't mention anything about null which leads me to believe I can't do what I'm trying to do. If It's possible to create normal condenser recipes with a single ingredient I'd appreciate another example because this has me stuck.