Beautification & Cosmetic Suregry

If this is to restore the natural color, this is permissible. However, you must cover it from non mahram.

You don’t need to use only henna. You can use any similar dye providing that it doesn’t form a layer or a coating on the hair but rather only gives it a color.

This is not permissible.

Yes, provided you cover it in front of non mahram men.

Tatooing your body is totally prohibited in Islam. You can get cosmetic surgery.

As long as it is not gold, this is permissible.

No problem in using it.

Dreadlocks are made of using one own’s hair by twisting and locking them and this is permissible. In case of wudhu, wiping over the head is sufficient, while for ghusl, the water must reach the roots of the hair and your scalp. You say the water reaches the scalp / roots, so this is permissible.

This is permissible

No.