Wearing wig is allowed in Islam, but if a woman wears it, she must cover it as a part of her Hijab obligation. Some Jewish women wear wig and consider it a full cover of the hair but in Islam wearing wig does not mean any change in Hijab obligation.

Those who need to wear wigs should not hide it when they propose or are been proposed for marriage as marriage must be built on true facts about both with out hiding such things.

Wassalam

The Qur'an is rather clear that everyone is responsible before Allah for his/her sins. While we may hope for intercession from the Prophet (S) or others, and it is fine to pray that other people be forgiven, it is not possible for one person to stand in for Allah and make the decision to forgive their sins.

We might sometimes get an idea that someone has been forgiven for something and reassure them, but it is not our place to issue a guarantee that this person has been forgiven.

The purpose of hijab is modesty and decency. The means of doing that is left to the individual, rather than specifying that certain clothes are allowed or unallowed, especially because what looks modest and decent on one person may look different on another, and fashions are always changing.

If you are asking regarding your daughters, perhaps you could talk with them about what appears modest and decent.

Regarding tights, it could be argued that they are not generally considered to be "clothing" in an outerwear sense. 

Nahj al-Balagha is an excellent source for understanding what the dunya is for human beings. What the dunya is depends upon how you see it and what you do here.

'The Message' by Ayatollah Ja'far Sobhani.