Can I just erase previous \Update and \wyUpdate?

You must keep your original files for your application (the only place they're stored is on the disk -- wyBuild doesn't tuck them away anywhere special).

Regarding the files that wyBuild generates:

• Your wyBuild project (*.wyp): Never delete this. In fact, make sure you make backups of this file. Among other things it include your signing-keys that are used the verify updates actually come from you.
• The client.wyc & wyUpdate.exe files: You can delete them or keep them around. It doesn't matter because you can regenerate them by clicking "Build wyUpdate" inside wyBuild.
• Your "yourapp.X.to.N.wyu" and wyserver.wys files: You can keep them around or delete them -- it's up to you.

But to be clear, once the .wyu and .wys are uploaded, the local copy is useless (except for backup purposes)?

Similarly, we can even delete these from the server and regen them using the .wyp (and the app files that the .wyp refers to)?

And ultimately, we can delete the previous .wyu files from the server each time we add a new version to the .wyp, because it generates yourapp.X.to.N.wyu for every version 1..[N-1], making all prior .wyu files irrelevant?

Thanks again for your assistance and patience. I think I'm about done with implementing wyBuild, but I want to make sure I've got it right up-front, w/o larger gotchas blindsiding me later. 🙂

But to be clear, once the .wyu and .wys are uploaded, the local copy is useless (except for backup purposes)?

Similarly, we can even delete these from the server and regen them using the .wyp (and the app files that the .wyp refers to)?

And ultimately, we can delete the previous .wyu files from the server each time we add a new version to the .wyp, because it generates yourapp.X.to.N.wyu for every version 1..[N-1], making all prior .wyu files irrelevant?

Yes on all counts.