Qadha Salaah

Going for umrah when one has outstanding qadha salaah

Q: Alhamdulillah by the mercy of Allah, I have been consistent with my salaah with Jamaat for many years, and have no qadha from the age of 17 onwards. However, before that unfortunately I used to miss most of my Salaah. 

My family wants me to go for Umrah but I don't feel it to be the right thing for me to join them, as I haven't completed my qadha salaah yet. I feel it's doesn't make sense to do that great but nafl amal when a compulsory amal is outstanding. I would feel extremely uncomfortable visiting the Kabah Shareef and Madinah, including the mubarak qabr of Nabi (sallallahu alaihi wasallam), and then conveying the durood with such major sins and unpaid debt on my shoulders. I understand that there is obviously barakah in Umrah, but there might be barakah in making qadha salaah as well (in my opinion). 

In addition, I find that my concentration and devotion to any nafl amal is weak and I always feel that I'm wasting time since I'm not prioritizing what is more important in the sight of Allah. Please advise.

Performing qadha salaah in the masjid

Q: I have heard that one should pray Qadha prayer in solitude so that it should not be revealed to anyone that one is praying Qadha prayer. Is this true? 

If so, then there is a problem that in a house where one does not get solitude and it is not possible in the mosque, then what should one do in such a case? 

Then can one pray Qadha prayer in front of the family members or in front of everyone in the mosque.

Fidyah for a person who suffered from dementia

Q: A man passed away, leaving behind his wife, a son, two daughters, a brother and a sister. 

Let's say he left an estate valued at $100,000. He had verbally expressed his wish to give one-third of the estate to charity, but there is no written will. 

How should his estate be calculated and distributed according to Islamic inheritance laws? 

Additionally, because the deceased was ill for the last six months and suffered from dementia, he was unable to perform Salah (prayers) during that time. Should Fidyah be paid for the missed prayers, and if so, from which portion of the estate?