So, long story short, I accidentally moved an inhabited house in the Lots and Houses bin. I panicked, closed the game using the task manager, opened it up again, and placed the lot back where it was from. The family relationships seem to be fine, but all of my "not related" friendships are gone, I can just reconstruct them with SimPE or something. I'm not worried about that, I'm worried if my game is corrupt if I did that. I don't want to run like hoodchecker or stuff right now because I fear it might make things worse. Should I be worried?!?! HELP!

(For reference, I'm playing a cleaned premade hood by meetmetotheriver; Pleasantview, specifically.)

While I believe that it is possible to fix it if you don't place the lot back, I think that you duplicated all the characters that came with the lot when you placed it back. Can you check in SimPE if clones were created?

It is quite likely you've caused corruption in that particular neighborhood, though the effects may not show for a while yet. The problem is that any broken relationships to other sims in that neighborhood could potentialy be so wide-spread that it's difficult to fix it all.

This is why doing frequent backups is so important. It's much easier to fix a neighborhood with a backup than having to find all potential issues in SimPE (chances are you may not find them all).

I'll have to check this when I get to my PC, but I'm pretty sure that relationships are deleted entirely. And the game duplicated every Sim that appeared in memories and the family tree of Sims that were moved.
EDIT: Moved the Pleasant family in a fresh Pleasantview into the lot bin and back. All relationships between the original Pleasants (which were left in the hood as unlinked, no character data Sims) were deleted. After placing them back, the game generated 29 new files, including everyone from Pleasant/Burb family tree as well as extras from their memories (Dirk, Dustin, Cassandra, Gordon, Kaylynn). But 25 of them were unlinked/no character data.

The game would have given you a pop-up asking if you are sure you want to do this. Do you have a recent backup? I would use that.

No, I have not backed up this hood yet because it's pretty new. Welp, time to start over I guess...

Yeah, checking in SimPE there's now two Cassandra Goths. fuck fuck fuck fuck fuuuuuuuuuuuuuuuuuuuuuuuuu

There may be a way to get it back to the way it was.

Go to the hood folder and right click on N001 or what ever the number is for this hood.
And chose to restore older version.

If you're unable to restore the previous version like marka93 said, you can still restore character data to all Sims that are missing it, and then delete the clones with the Batbox method. That should fix it.

I use Linux, so "previous versions" don't exist.

Also, @mate54 too risky.

Unfortunately, that's the only way you can fix this without restoring previous versions. You might get away with just correcting the relationships in game, but the duplicate Sims will still remain.

You made a mess then made it ten times worse by moving them back into the 'hood.
When the game moves sims like that they remain in the 'hood but are 'unlinked', that means their character file is stripped of 3d resources and just enough remains to contain the GUID, thumbnail and name (catalogue description). that is enough to keep the memories, relationships family ties etc. of other sims in the 'hood intact. The game also adds into the lot file unlinked copies of any sims that the sims being moved have any relationships and/or memories of to keep them intact.
When you moved them back in fresh copies of those sims with new GUIDs were added back into the 'hood as well as all of the unlinked sims with new GUIDs. If you now restore their relationships with the sims they were previously friends with then they will all be friends with two sims with the same name and identical appearance. Ideally you'd need to remove the relationships and memories to the original sims first, that also extends to all of the unlinked sims that were added to the 'hood.
As it is it won't cause neighbourhood corruption but is a mess you'll probably never get rid of.