(2) What is the ruling of changing of name?
بسم الله الرحمن الرحيم
You may keep the name Rasel Ahmed but since it does not have good meaning hence if you want to keep some other name then you may do so. It is better if you choose a name among the names of the Prophets and Sahabah, for example, Musa, Isa, Dawood, Muhammad, Abu Bakr, Umar, Usman, Ali, Huzaifah, etc.
Allah knows Best!
Darul Uloom Deoband