I would very much appreciate if these two questions can be answered for me.1) I would like to have full explanation on Qasar [Shortening Salah] for someone performing Hajj. For how many days is he allowed to do this, and after how many days he is not allowed?2) Tawaf-al-Ifadah for a woman in her menses.

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

A traveler is allowed to shorten his prayers (i.e. four to two) as long as his traveling is for a permissible goal and his destination is more than 83 km away. This ruling applies until he returns to his home or his consummated wife's habitation, or if he intends to stay for four days. When he arrives at his home or his wife's habitation, or completes the intended stay of four days, then he has no the right to shorten his prayers. This ruling applies to the one who performs Hajj and to any traveler, whose travel is permissible. But, it is highly recommended for the Hajji to follow the Sunnah in performing the four Raka'h prayers shortened and combined at 'Arafah and Muzdalifa. In simple words, he has to combine and shorten al-Zuhr and al-'Asr in the time of Zuhr while he is at 'Arafah, and combine al-Maghrib with al-'Isha (two Raka'h only) in the time of al-'Isha in al-Muzdalifa.
Also, the Hajji is advised to shorten the four Raka'h prayer (without combination) on the 8th day of Zul-Hijjah.
Tawaf (the circumambulation of the Ka'ba) is one of the pillars of Hajj and 'Umrah. In other words, Hajj or 'Umrah becomes invalid if one does not perform this Tawaf. If one performs Hajj, then this Tawaf is called al-Ifada. As for one who performs Umrah, then it is a pillar of Umrah.
The Hajji, male or female, must be with complete purification while performing this Tawaf. Otherwise, this Tawaf becomes null and void. In simple words, one must be with ablution, free from Janabah (which necessitates a bath), and for a woman free from confinement and menstruation. This is the preponderant opinion among Muslim scholars, both al-Salaf and al-Khalaf (ancestors and descendants)
The Prophet (Sallallahu Alaihi wa Sallam) said to his wife Ayisha (Radiya Allahu Anha) while menstruating at the arrival of Makkah: "Perform all the ceremonies of Hajj like the other Hajji, but do not perform the Tawaf of the Ka'ba till you get pure (from your menses)". [Reported by Imams Bukhari and Muslim]
Therefore, a woman who is performing Hajj or 'Umrah has to follow the above-mentioned Hadith and to wait till she becomes pure from menses to perform the Tawaf. But, if she faces unbearable circumstances such as her company travelling and leaving her alone, then she has to stay in her state of Ihram and travel with her company and when she becomes pure she returns to perform Tawaf al-Ifada. If such a final solution is impossible, then she has to put a sanitary towel between her legs and performs al-Tawaf, since she is compelled to do so.
Allah Says (interpretation of meaning): {Allâh burdens not a person beyond his scope. …}[2:286]. He also Says (interpretation of meaning): {…and has not laid upon you in religion any hardship, ….}[22:78].
This is a form of Divine Mercy and a sign of the upright and easy Sharia of Islam.
Allah knows best.