1.The word for ACCENT in Bengali:: "কথা","স্বরাঘাত". "উচ্চারন" is also correct. But I would rather prefer "স্বরাঘাত" than "উচ্চারন".
2. আমি ভারতে বুধবার পৌছলাম::::: accurate
3.The above three words are being used in the different situation in India.For instance, if you are communicating with someone in HINDI then you might wanna use "BHARAT".
ex: Mera Bharat mahan(HINDI) ===My India is great
Aurangzeb, one of the greatest of the Mogul emperors of Hindustan, was the third son of Shah Jahan.
strictly speaking, in India the usage India is more common than Bharat, Hindustan.
In general conversation, we barely use the word "HINDUSTAN".
So Bengali people use "BHARAT", non-Bengali people use "HINDUSTAN" in their general conversation.