The editor gives warnings for a reason.

This changeset disconnected the motorway link while moving the intersection to the wrong location.
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/174044228

What was the source used for these roads?

To be more specific, the issue with this approach is that when someone marks the road open again the turn restrictions aren't likely to be removed since the access tag is the usual method to mark a road that's closed.

Did not folow task instructions
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/167447296

The highway definitely doesn't go over one track then connect to the subsequent one.
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/165457393

reverted

changeset/173949408

This changeset connected a bridge to the road it crosses.
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/173268766

This changeset connected a bridge to the road it crosses.
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/173925523

Access restrictions should not be tagged with turn restrictions
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/168993087

reverted. please provide a source for major road deletions

changeset/173771486

My suggestions:
1. Avoid using advanced tools like reverters except to revert damage. (extra nodes are not damage.)
2. Remove "4. Nodes should never be created in our activity (we split at existing nodes). Any added node is treated as an unnecessary geometry change and will be reverted, hence the “unnecessary node” comment." from your guidelines. It's a broad rule that doesn't provide any meaningful quality assurance.

reverted. Needs to be manually fixed

You can use
`(((._;>;);<;);>;);
out meta;`
instead of
`(._;>;);
out meta;`
at the end of queries to get all connected ways so that you don't inadvertently move another feature.

changeset/173479852

This changeset moved a lot of roads incorrectly.
Reverted.
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/173472314

How are these "unnecessary" nodes determined?

reverted

changeset/173473011

This changeset removed a section of freeway.
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#REVIEWED_BAD #OSMCHA
Published using OSMCha: https://osmcha.org/changesets/173312912

osm.wiki/Good_practice#Don't_map_temporary_events_and_temporary_features