I will be upgrading to Catalina in the near future. I know that 32-bit apps will not run and I intend to delete them. My question: Will the installation move them automatically to /Incompatible Software or will I have to manually delete them?

Not being in Catalina, I can't answer definitively, but I'll bet the farm that even if macOS begins the job you'll have to complete it by hand.

Having edged into Catalina through a series of beta releases, I have little direct experience with the release installer, but IIRC the initial installer gave a LIST of incompatible apps but they were not automatically removed. I do know there were additional 32bit executables (not apps) that were not on the list that had to be removed by hand. I found the Etrecheck/Etrecheck Pro Power User Package a big help in identifying and eliminating that detritus.

I was referring to the ancillary files that are created either during or after an app's installation, which I doubt that macOS will even attempt to ferret out.

My new iMac arrived with Mojave installed and I am so glad! My old Mac Pro is still working, but I was so afraid to lose access to my Adobe CS 5.

At least, I thought, I would be able to run Photoshop in Catalina, as it is 64-bit. But, NO!!!

I formatted a SSD as APFS, copied my Mojave system over, then installed Catalina. It seemed to take forever. I could not launch Photoshop. System Report says that Photoshop is 32/64-bit, so I guess Catalina will only launch fully 64-bit apps.

Also, you should run all your Adobe uninstallers before installing Catalina, because the uninstallers are also 32-bit.

There was a folder in Users called Relocated Items, but nothing was in it. All apps were left in place, but had crosses through the ones that would not launch.

Bottom line: I believe Mojave will be my last OS. I have to hope this iMac will run for another 10 years...

FWIW, I tried running Photoshop CS5 in Mojave and it worked but was temperamental. I bit the bullet and subscribed to Photoshop CC and am very pleased with it. The improvement in selection tools, alone, is worth the price of admission. While I object to Adobe's subscription policy, I can well afford the $10.99 a month that it costs.

Thanks for pointing out that apps that would not launch were crossed out. That will make life simpler when I upgrade to Catalina, which I plan to do as soon as 10.15.2 is released. I have successfully migrated everything from Entourage 2008 to Mail and find, to my satisfaction, that I like Mail. My better half wasn't so sure but now she is used to it.

With the exception of Acrobat Distiller, I am running the entire CS5 Design Standard Suite in Mojave. I had to do a .bak renaming trick to avoid the crash-on-quit problem, but Photoshop, InDesign and Bridge are working fine. Mind, I am only doing simple stuff these days, no fancy layering or typography. I've only launched, opened an old file and quit Illustrator to see that it didn't crash.

Acrobat works okay, but I've been weaning myself off of Adobe products. I use Preview or Finder for pdf duties and all my frequently used InDesign files have been recreated in Pages.

I'm fine with Mail, but my old Mac Pro still has Outlook on it with years of archived mail. Using the Mac Pro via Window Sharing is working quite well, you just have to get used to the smaller window size - 1920 x 1200 pixels looks very small on a 5K screen!

The Mac Pro has very pared down versions of High Sierra and Snow Leopard for apps that just won't cross the divide...

I don't know if this will work with Outlook, but with Entourage 2008 I did the following:

1. Drag a folder from Entourage to the desktop. Depending on how many emails are there, it may take a minute or so, but it will appear on the desktop as an Mbox file.
2. Go to Mail > File > Import Mailboxes...
3. Select "Files in mbox format" and follow the prompts.
4. Again, this may take a minute or so, but an Import mailbox will appear in Mail, with a subfolder. The emails are in the subfolder.
5. Drag the files to the mailbox of your choice, then delete the import mailbox.

This procedure worked well until I tried to import a folder that had over 10,000 emails. When I selected all and dragged them into my Inbox folder, Mail choked. I quit Mail, relaunched it, and then dragged about 70 at a time. This was tedious but it worked. Be aware that Mail will mark all of them as unread. I selected all and then went to Message > Mark as Read.

Thanks for that. When I'm feeling a bit more patient than I am today, I'll give it a try......