Consider sticking with the release that's doing the job for you...and testing newer versions when you have time to spare.
It's tough to diagnose these annoyances without seeing them. Try to link screen grab videos of each, and post links here.
What version is doing this? Look at the bottom-left of the screen, or click the three-lined Menu at the top-left, then HELP | ABOUT.
Here's the latest 64-bit release. See if it does the same.
Have not seen reports or experienced the mouse wheel scrolling the timeline up. The wheel should contract and expand the timeline horizontally.
This may be a mouse setting. Open Control Panel | Mouse and confirm that neither Click Lock or Snap To (pointer options tab) are enabled...
How was the clip duplicated, and where was the dupe placed? Select the clip, then press <ctrl-C> to copy it. Position the cursor, and <ctrl-V> to paste. Or right-click on the clip and use the COPY/PASTE options. Or click the Menu and use the Edit options.
This video has a silent gap, and the cursor does not jump. When a clip was duped, as described above, then pasted into the gap, it played normally.
Record_2025_02_28_21_52_56_952.mp4
As to your earlier thread on dialog boxes not appearing at the center of the UI ...
It has recently come to my attention that this is a feature being tested for its convenience value, to minimize pointer repositioning. Whether it will make the grade in the long run is yet to be seen. If you find this annoying voice your opinion here.