Method of Salaah

Keeping the head straight during qiyaam

Q: 

1. Would it be disliked if someone bowed their head till their chin touched or almost touched their upper chest, in the standing or sitting positions of the prayer (while keeping their eyes at the various sunnah positions during the prayer)? If so, for what reason would it be disliked, and when would it not be disliked? 

2. If they did this out of feeling comfortable, would it be disliked?

Acquiring concentration in one's duas and salaah

Q: Please advise how to soften my heart. I recently cannot cry. No matter how afraid I am of my sins and meeting Allah Ta'ala, I cannot cry when making dua. If it's my medication, do I stop it? What if I battle without my medication? At the same time, I'm worried about becoming hard hearted. 

I also cannot concentrate at all in my salaah. How do I become a better Muslim?

Imaam starting the qiraat while one is reciting thana

Q: In Prayer behind the Imam, if the Imam starts reciting whilst one just started reading the Thana and he was in the middle of saying اللهم in the Thana but the Imam had already started so he just finished saying Allahumma then he stopped reading the Thana, 

1. Would the prayer be valid? 

2. Would he have missed a Wajib and have to repeat the salah for missing a Wajib?