This is going to be a big ol post. I'll start by pointing out that your map has a leak. This ought to have been caught before uploading, as the 3D skybox breaks and causes players to render the entire map a second time if they so much as look in the wrong direction. Its quite likely that if the map was played by a full server, that the map would crash! Always make sure to check for leaks!
These checklists are a bit old, but still very useful for remembering common issues. They also touch on checking for leaks using pointfiles.
https://tf2maps.net/threads/tutoria...ou-have-all-of-this-before-going-alpha.18663/
https://tf2maps.net/threads/readme-1st-common-tf2-mapping-mistakes-and-how-to-fix-them.3050/
As far as the copied elements, RED spawn on the floor level is only somewhat retextured. The wallpaper was swapped out in the back, as well as the glass door for a wooden one. The only thing really different in the room is the ceiling (not pictured), and thats because you added a basic balcony up there, otherwise the geometry of the room is identical. This example bothers me because you were denying that this was a copy.
It still looks the same as Manor's RED spawn. These sorts of small changes don't make the usage okay. I can tell between the original and your own pictures that you tried to rebuild the walls and in doing so didn't properly scale the wall panelling, but its the same room. You can't copy something so closely and say that they are different. The staircase and layout are still blatently copied.
The ceiling above last that was in gorge_event and also above the last point of Mann Manor was covered up, not removed, by a gigantic flat brush. You can even still see the stone ring that forms the bottom of it.
Viewing from just above the flat wood ceiling, we can see the hidden element:
And the original in Mann Manor for context:
The clocktower above second is the same prop as before, but the base of it has been covered by simple brushwork. The structure is identical in usage to the one in sunshine_event.
In Hell, you deleted the hellstones that were jutting out from the platforms, and added one additional large rock formation on the right hand side. Being unable to make Hell from scratch ought to be a challenge, or at least a learning experience. You could have looked at Hellstone's Hell as an example of how to do it properly, but you used the same arena and made very minor changes yet again.
Upon further inspection, there is yet more! The Mann Manor chapel is in the background of the second point.
Yours:
Original:
The entrance cover from Mann Manor is also the entrance cover for the mansion, albeit slightly edited into an L shape. The stairs at the base are the same though.
Yours:
Original:
I'm not entirely sure about this one, but there may also be a guest appearance of the hallway hole from Mann Manor as well.
Edit: The holes are unique
Yours:
Original:
The hallway hole from gorge_event is completely unchanged, so I didn't picture it here.
On your Steamcommunity page you told ICS that you hadn't copied anything from Mann Manor, its pretty clear thats a lie. This is a serious topic, you can't just joke about copied stuff.
You may have gone a bit overzealous with the playerclipping. Many in map zones are clipped without context. The detailing is a bit excessive as well, with some rooms being coated in props, all the way up to the rafters. As the map is not optimized, this crowded detailing could cause trouble for your testers.
So lets talk optimization. This site has an excellent guide on optimizing your map:
http://www.optimization.interlopers.net/
Many small actions like making your balcony railings or small broken bricks into detail brushes would help that hallway run a lot smoother and likely lower the amount of time it takes you to compile the map.
What I want to say with all these pictures is that you need to take more time with your personal work. Copying elements of your favorite Halloween maps like in the examples above was hopefully borne out of respect for them, but you only altered the elements that were pointed out in Crash's post, and for several of them very superficially. You must have known that you had copied other elements from those maps without permission.
The parts of the map that are entirely made by you, like the capture point pictured in the thumbnail here, are pretty good! Your own personal work with time and practice is what will end up making this map yours. With more practice, by asking questions and reading up on Hammer, all these problems can be fixed, but you can't rush your work and substitute in other peoples'.