Question: 

1) What is the ruling of the Qiraat if an Imam made Salam after one Rakah? Kindly advise the rulings if the Imam realises the mistake during the Salah time, as well as the ruling if he only is informed about it the next day.

2) What is the ruling if the Imam does not know Arabic and makes a mistake which changes the meaning completely? Does he only repeat the Qiraat, or does he have to repeat the two Rakats? Does the ruling change if they realise in that Salah time, or if they realise only the next day.

Question: 

Is it permissible to make Salaam to a person that is busy reciting the Quraan Sharif or partaking of meals?
It is Makrooh to make Salaam to a person that is engaged in the recitation of the Quraan Sharif or partaking of meals. If someone makes Salaam at such an occasion then replying to such a Salaam is not Waajib. Similarly, it is not Waajib to reply to a person that greets whilst the Adhaan is being called, as reply to the Adhaan is Zikr and replying to someone whilst engaged in Zikrullah is not Waajib.