Touching one's mother with lust

Q:

1. I know that if someone touches his mother with lust, it will break his parents marriage. I want to know if it is permissible for his (the one who touched his mother with lust) children/grandchildren to marry his brother's/sister's children/grandchildren? Are their children/grandchildren allowed to marry each other?

2. Can he (the one who touched his mother with lust) marry his mother's brother's daughter?

3. If the thought comes to mind that a perosn touched his mother with lust during his childhood, but he is in doubt whether he touched or not. What should he do now?

Performing Salaah with jamaat at home

Q:

1. If I missed the prayer with jamat, can I pray with my family members (wife, sons, daughter) at home?

2. Can I miss the congregation prayer at the masjid and pray in congregation at home because the imam of the masjid makes masah on normal socks?

3. If I am sure that I will miss the jamat, is it compulsory to go to the masjid and pray alone or second jamat?

4. I hear the azan and iqamat and complete namaz but I am very tired to go and pray in the masjid, can I pray at home later with my family?

5. For Asar prayer, instead of praying with jamat in a Hambali maslak time, can I delay the prayer and pray (alone or with my family) at home after the Hanafi maslak time begins. (I listen to the complete azan and iqamat and jamat from the masjid's speakers).

Not exposing one's sins

Q: I wanted to ask which sin is lesser of the two evils, exposing one's sin or lying? I am asking because if someone asks if you have comitted a sin, is it permissible to lie and say you haven't? Would that be better than exposing your sin? In a situation where you cannot avoid the question?