What I did for sketch constraints, is recorded a Macro with the macro recorder that goes to the constraints I want. Then I assigned accelerator keys to run that macro. To do this look in the help for Create new commands to point to the correct macro.
Once you get your new command into NX, you can assign an accelerator or keyboard commands to this new command. Hope this helps a bit.
I know click on sketch curves and the constraints pop up. I am from I-deas and I like to pick the constraints type first then pick the objects. Old school. Old Habits.
I agree with SDETERS, do a search in here for Macro Buttons and you should get results that will help you.
The process has not changed much in the last few years so don't worry too much about the oldness of the post.