1. I do not have access to WRC 107, as I never purchased it, but it currently runs ~98 USD from WRC. I don't know if you're going to find someone willing to transcribe these calculations, especially when there are better alternatives to this method, such as NozzlePro.

2. My understanding has always been:
SUS: W+P+...
EXP: OPE-SUS
OCC: OPE(including occ loads)-OPE (excluding occ loads)

Perhaps someone with the appropriate WRC materials can speak up.

3. Again, I don't know what WRC 107/297/537 says, but it's a requirement of B31.3, therefore, it's included in CAESAR's module.

4. Your end user accepts risk for defining what consists of an occasional loads, and should they choose to pass the responsibility on to you, then that's on you.

5. I would surmise that you would be applying non-EXP effects approximately twice in your expansion stress analysis, though you might want to run a few tests and check the output.