Correcting one's intention

Q: I was wondering what would happen if a person for example buys a book with riya, but then makes tawbah and then uses it sincerely for only Allah Ta'ala? What happens in these situations when someone tries to follow Deen but he has corruption in his intention but later fixes it. Will he get reward for it?

Celebrating birthdays

Q: I have a question regarding birthdays. Can we as Muslims celebrate birthdays? I know the answer is no, but a friend of mine told me that if you just cut the cake and only invite one or two friends just to make your child happy, then it's not gunaah and you wont be punished for it. So is this true? Can we celebrate our child's birthday just the way she said?

Losing concentration and composure in Salaah

Q: I have a mental disability where I have psychosis, ocd, and split personality disorder. Sometimes in my Salaah it is not within my control to control the peace of mind and thus my ustaad ruled that for me, being in a state of peace or not does not count for me and my salaah will be fine. My question is, I sometimes do my Salaah when I am at peace but I mistakenly make the mistake of being not calm due to my illness. What should I do in this case with the Salaah that I have ruined in terms of I had already had peace in my mind and intentionally by accident got not peaceful?

Anal sex

Q: Since the time when my wife gets pregnant, since then she feels intense pain in vaginal intercourse. We have treated for it a lot but no medicine is useful. Last time when my wife got pregnant I managed somehow to live without intercourse for 10 months (during his pregnancy) but this time its not easy for me to control myself from intercourse. But in vaginal sex she suffers unbearable pain so is there any way that I can do anal sex for my pleasure as well as for her sake. Please guide me what Shari'ah says in my case.