[Your Gigs cannot be promoted right now, we'll notify you as soon as this changes]

You might check out this article for the requirements of promotable gigs:
https://www.fiverr.com/support/articles/360017729338

Here's a short bullet point list from the article:

• You are a Level 1, Level 2, or Top Rated seller.
• Your Gig scores are 4.7 in the public rating.
• Your Gig has at least 20 reviews.

[Fiverr Early Payout Feature]

I have the early payout feature, however I don't use it.
There is a fee for each transaction.

[Country Location Change]

How can i change my country location italy i just recently shift italy so i need to change my location

Have you tried reaching out to CS?

[My gig is hidden from searches]

Do you mean like posting a link to your gig from your website?

I don’t know if you get any boosts from Fiverr, other than the fact that you might gain some extra visitors through your site.

Definitely don’t see an issue with advertising your Fiverr gig elsewhere.

[Fiver Advance Cash Feature gone?]

You might reach out to Fiverr support.

[Seller is falsely advertising and won't cancel order]

If the money is not a concern. A bad feedback would probably make the biggest impact.