Salaah

Wudhu breaking by laughing aloud in salaah

Q: I have some questions regarding laughing aloud (such that another person can here you) in salaah. I have seen multiple views and do not know which one is correct. 

1. Can you touch the Quraan afterwards (i.e. is it hadath or not)? 

2. For those who say it is for reprimanding the person, not hadath, according to them can you make tawaaf with that wudhu, or is tawaaf similar to salaah therefore tawaaf is invalid with that wudhu?

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?