In Morrowind Construction Set, is there a quick way to disable restocking items on merchants? I know I could go through each merchant and change the negative item values to positive ones, but considering that would take many, many hours, I was wondering if there was just a "switch" I could flip somewhere to disable them all, or toggle the amount of time it takes for the items to restock similar to the merchant's gold.

If you have programming knowledge, you could try doing something like the following:

1. Study the information available online about the file formats used by Morrowind.
2. Write a program that reads the information from the .esm file and writes out a .esp file with the modifications need.
3. Run the program, then test to make sure it actually works.

You can find some documentation of the file format at: (It appears the NPCO sub-record of the CREA and NPC_ records is what you are looking for.)

Note that looking at the files with a hex editor might be a good idea if you plan to take this route.