Two of my apps refuse to load and open.

Applications have a shelf life, and if their developer does not keep them current (and tested) with the current release of macOS, they can fail. Since Catalina only supports 64-bit applications, those applications that are not 32-bit, 64-bit with 32-bit helper applications, or 64-bit and not yet compatible with Catalina will fail.

Cuprum (v1.7.16) was last updated 4 weeks ago, and should not have crashed with 10.15.6, though its compatbility indicates 10.12 or later. Contact the developer about your crash occurrence.

It pays to keep Pages, Numbers, and Keynote up to date, in case Apple releases a future version that requires a newer major operating system upgrade. These applications are all presently at v10.1, and you have v10.0.

About the only thing left is a re-install...

1. Start up from macOS Recovery

To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following combinations on your keyboard. Command-R is generally recommended, especially if you never installed macOS Sierra 10.12.4 or later… https://support.apple.com/en-us/HT204904#notupdated

Command (⌘)-R

Install the latest macOS that was installed on your Mac.

Delete these files & restart...

/Library/LaunchDaemons/com.RunappDaemon.plist

~/Library/LaunchAgents/com.ecamm.printopia.plist

~/Library/LaunchAgents/com.Runapp.plist

~/Library/LaunchAgents/com.Opera_Helper.plist

~/Library/LaunchAgents/com.apple.SafariBookmarksSyncer.plist

~ tilde indicates hidden Home Library.

Apple hid the Users' Library folders...

Method 1:

1. From the Finder, select the Go menu at top of the screen, and choose Go to Folder.
2. In the window that opens, enter ~/Library, and click Go.

You can also download and run the free version of Malwarebytes to get rid of the adware. It was developed by a long time contributor to these forums and a highly respected member of the computer security community. 

Not enough useful data for me in a crash report.

You can save us asking dozens of questions by submitting a report from this App for us to look at…

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.

https://www.etrecheck.com/

To find out if it's system wide or user specific, try this...

Open System Preferences>Users & Groups, unlock the lock, click on the little plus icon, make a new admin account, log out & into the new account.

Does it work in the new account?

I was gong to point out how much potential adware showed in the report but your reinstall post wasn't visible when I started typing. Gotta love this forum software!

I'd be inclined to run Etrecheck again to verify that the new install is clean.

Did the developers confirm that 8GB RAM is sufficient for their apps?

Can you try downloading one of the non-working ones again?