First, I'd like to say THANK YOU for the feedback and thank you very much for playing the map. I'm going to try and address your concerns one by one as you listed them.

1. Adding modifiers would further make equipment OP. People already complain about overpoweredness as is. And to them I say the following:
The Items are to represent the real CSOTN item you would find in that chest. Or it's closet Terraria equivalent or substitute. So if you'd find Gold armor in COSTN, in Terraria you're going to also find Gold armor, or it's closet substitute (even if it's made of a hardmore ore/ie OP). Overpoweredness wasn't taken into account because in CSOTN Alucard quickly becomes overpowered anyways.

A lot of the repeat chests are Sub-Items in CSOTN, for example all the Yo-Yo's and Hatchets (Axe) and Toxic Flasks (Holy Water). You are meant to sell repeats to the Librarian, or discard them if you like. This is a 1:1 replica I did as a paint-by-numbers. It's one for the fans, not to provide balanced progression. The last two fights (Empress and Moonlord) are so difficult I kinda felt giving the player some overpowered equipment was merited anyway.

2. Unsure how to implement this as I do not know of a way to change difficult on the fly unless it's journey-mode only and then I would yes, have to write out rules and place them at different places so the player knew when to switch. The problem there is Terraria (and also T-Edit) only allows so many Sign-Posts and the entire map is already dangerously close to the limit as is.

3. The wired area you are referring to that continuously spawns enemies is the first two zombie halls in the castle entrance? If so, that is by design, as in CSOTN so long as Alucard is in those rooms zombies continuously spawn every few seconds. In some of the dead area's I had planned to revisit many and add in more statues, like bats, and random skeletons exactly as you recommend I've just been lazy and tbh haven't touched the project in a good while.

4. All Relics abilities were replicated by Terraria items or their closet equipment/ability. Actually adding in CSOTN's relics would require mods and I do not know how to mod that well.

5. I didn't create the Richter character file, however I will play-test it, investigate and try to remedy and update the character file.

6. There are many Easter Eggs (Some people still haven't found). There are many signs in the background that have hidden messages written on them that reference other games, books, movies, media, even bible quotes, ect. One example is all the jail cells in Olrox Quarters have a prisoner number and name written on them. The names are all the IRL historical figures suspected to be the real Man in the Iron Mask. There is also two beautifully made pixel-art recreations of Alucard and Maria in the center of the castle (Shout out to Ghost-Slime) that are huge. I even added a hidden thing outside the castle, in case anyone familiar with the chapel-swordbrothers glitch "cheated" their way outside. I do not believe anyone has reported finding it yet.

and lastly "Death skip literately being replaced with a D&D Reference":
You didn't enjoy that? It took a lot of thought and effort to do that, after careful consideration of how to tackle Death stealing your stuff. Because there is no real way to make that happen except a trashcan and the honor system. The biggest problem there is that that room is before the first save room inside the castle, so if a player stops there and discards their starting gear and then dies before visiting the first save room and banking their spawn point, they spawn back in the prologue and have to walk all the way back this time devoid of gear and that first zombie hallway is pretty much impossible for a naked character. So I wrote that entire cutscene dialogue myself as an attempt at humor to circumnavigate the entire debacle entirely. I am open to suggestions on how to improve it.

Thank you so much for the feedback. Im going to playtest that character file and do a map update soon fixing as many of the issues you brought up that I can. In the meantime, if you friend me on here I can send you a link to my discord (I dont remember if I posted a link anywhere in here). If you don't want to and prefer to respond here that is great too. I will read, attempt to fix or address and update, and then respond back to you as soon as I can. Thank you again for playing and for all the input.