🚀 go-pugleaf

Yes, don't bother yourself with CMYK issues unless you are doing commercial 4 color press output.

Yes, mapping your JPGs imported by reference in FM to the JPGImportByReference macro in WWP is easy and preserves the integrity of your source images without further processing.

Yes, JPGs are lossy and are not ideal for screen captures. Use BMP (though they can be heavy in file size), GIF (though they can be limited in colors expecially if using a pre-defined color palette), or PNG (an ideal format, in my opinion).

No, you don't want to map your JPGs to PNG. The degradation has already taken its toll in the JPG format. Converting them to PNG will result in a PNG of your lossy JPG - no further loss, but no gain (except maybe a few Kb lighter in file size).

Mapping TIFFs to JPG results in lossy compression of your TIFFs in moving to JPG format. Not a desirable way to go.

For now, you might as well use the JPGImportByReferece macro in WWP, but going forward, capture your screens in a non-lossy format and use non-JPG macros in WWP. Think of it as a maintenance step.

At least, that's what I'd do. That is, unless I had the time to recapture all screens in PNG format.