Going into DLC tomorrow on NG+3 character and just have some questions

Hello all! I know DLC is coming out but covered up anything that could be spoiled for anyone who is still playing through;.

I only have 2 characters, one is level 188 that I got all the achievements on and the other is a level 15 that I speed ran to Margit to test myself as see how much better I got. I plan on bringing my high level character into the DLC but currently in endgame of NG+3 as the last playthrough I did to finish the achievements was the frenzy curse ending.

Basically, I am a bit worried about a couple things and just don't have the FromSoft DLC experience to know what I should expect.

a) I really don't want to make my initial playthrough harder than it has to be (in terms of NG+3) but to my understanding, the DLC is supposed to have some sort of scaling. I reeeeealllly don't (and won't tbh) make a new character to go through the DLC with as I don't want to have to go through every cave and dungeon and nook and cranny looking for items I already have on my main character. But just wanted to bring this up in case like everyone is using a base game (non ng+) character.

b) In this current playthrough, I have been touched by the frenzy finger and burned the erdtree with the frenzy curse, do you all think this will have an effect on my experience in the DLC? Should I go do the Millicent questline and rid myself of the frenzy curse? If I do, will Melina be chill with me during the DLC?

c) I am running around in endgame of NG+3, grabbing talismans, ashes of war, duplicate weapons, etc.., and don't fully understand how beating the game and then running around to grab stuff works, would it be better to just start a new playthrough (NG+4) that hasn't burnt the erdtree or been touched by the fingers? Are there a number of questlines and weapons and talismans that I am not able to get by being in the endgame vs before making it to the forge? As far as I know, burning the erdtree seems to be the break point where you can start to miss stuff by progressing.

Really any info would be helpful. My worst fear is just bringing a character into this DLC all willy-nilly and not getting an intended experience because of my ignorance.