Mojave upgrade bugs

After upgrading my MacPro tower from 10.13.4 to 10.14.6, a number of little things are broken.

For starters, Mojave seems to have blown away Dictionary.app's dictionary files. Where are they located, and how can I download them again?

Next, Quartz Composer .qtz files work fine everywhere except as screen savers. The system says: "You cannot use this screen saver with this version of macOS. Please contact the vendor to get a newer version of the screen saver."  I'm using QC 4.6.2. Is there a newer version available?

A number of Dashboard widgets broke. The ones I miss most are RadarInMotion and Weather. They just come up blank. Are widgets even supported in Mojave?

Is there some way to configure the Mojave screen lock window to show a "Sleep" button? It's a pain to have to log in just to put the system to sleep.

-Carl