I have done exactly what Thad is saying with the ops libraries. But i got sick of going through the import process and searching for the correct toolpaths i needed to import even though i had them labeled good like Thad's examples. Once you get all the toolpaths for all the different scenarios it can get into the 500 - 1000 toolpaths if not more. So what i did was design and code a window that sits in the levels manager with buttons and drop-down menus to automatically import what i need. I also made it for different materials so i dont have to mess around with changing tools or speeds and feeds. I pick to material i want, pick the operations i need and BOOM its imported at the red arrow and i just pick geometry.....Done! I just click and in seconds what i need is imported. I also use same window for doing other common everyday tasks as you can see in the pictures. It took many hours of work and coding but i'm so glad i did it.

Another tip for the contour parameters...even though you may have separate ops saved for the various options (2D, remachine, ramp, etc) within contour, go into each option and set each type's parameters the way you like them, then disable the option. To clarify, say you have a plain old 2D contour op saved. What if, after you import it, you want to change it to contour-ramp? When you select ramp from the drop down, all of your settings for ramp should be set already. Same with remachine, etc. Every contour operation in your library should be saved so that you can change contour types and those parameters are already setup. Does that make sense. I'm not sure if I'm describing that clear.

If you use standard level names, make a CSV file of your level names, then import the names into your MC file by right click in the levels manager->Get Named Levels.