Both are possible and both have been discussed many times on the forum.
For your first case, right-click on the "master" clip and choose Copy Keyframe Attributes. Then select as many clips that you want to match and right-click on them then choose Paste Keyframe Attributes. Note that masks and certain other edits (like CLUTs) are
not copyable attributes and will have to be applied manually.
A way around that is to use your second case - however that will only work with clips (including precut ones) from the Media Library.
To do this, copy and paste as many "master" clips as needed on the timeline, then one at a time drag a new source clip onto the existing clip from the library. From the pop-up menu choose Replace, and the new clip will replace the existing clip with
all edits (including masks and CLUTs) intact.
You may encounter minor problems in either situation when the duration of the master and copied/replaced clips differ. That's due to some tools/keyframes being anchored to the start of the clip while some are anchored relative to the end.
Depending on the specific edits you've made, you may find it easier to start with the longest clip as the master; while others may be easier to address in the copied clips if the master clip is shorter. Try both of these approaches out and see which one works best for your situation.