STOP SWITCHING TO THE NEXT CLIP WHEN I'M TRYING TO MANIPULATE KEYFRAMES
This is super annoying. I create a keyframe, let's say a motion keyframe. Set it to 50. Then create another one, set it to 100 and put it at the end of the clip. Then I scroll to the second keyframe and suddenly, Premiere has switched me to the next clip in the timeline for some reason. This is so annoying. Even moreso when I'm using my mouse to move the scrubber around, sometimes it juts me all the way to the end of the timeline. I can't imagine a scenario where I would want this behavior.
To add to this, there should be some padding around the clip boundaries in the keyframe window. So that we can clearly see where the end of the clip is, and where the last frame is. Just a small visual change but a big difference in usability.
To address moving to the next clip, just make it so that the playhead in the keyframe window will NEVER trigger selection of another clip, regardless of whether "Selection Follows Playhead" is enabled or disabled. Or, that it will not do so when the effect controls panel is active.
Sounds like you're putting the keyframe at the end of the clip instead of on the LAST FRAME of the clip, which is one frame back from the end of the clip itself. I do this a lot myself. When you just drag the keyframe to the end of the clip, it's putting it on the same frame as where the splice is, which is why it's showing the next clip, because that's the first frame of the next clip. Back your playhead up one frame, then move the keyframe to that frame.
Matt Badger commented
Another solve for this is to uncheck Pin to Clip in the Effects Controls hamburger (three lines, panel) menu.
Franklin Nin commented
If Premiere is selecting clips while you scrubbing is because the option "Selection Follows Playhead" is activate. You can turn that off by clicking Sequence, Selectiong Follows Playhead.