Concerned about my tokay's tail

[Andiamo]

I have considered the possibility of to remove the tail myself just in case, but I don't know how risky that is.

Definitely don't do that. The tail honestly looks fine to me. I've seen some geckos regenerate tails that look like that. You can also try GeckosUnlimited.com for more advice, but I think it's pretty normal from what I can see.

a Necrotic tail will become stiff, hard at the end, will shrivel and pretty much die.