What were the areas of conflict between the Bengal nawabs and the East India Company?

The Bengal nawabs wanted tributes from the Company in lieu of granting the right to trade. The Company was forbidden from minting its own coins and from expanding fortifications. The Company wanted to expand its settlement and wanted special privileges.

In the 18th century, after the death of Aurangzeb, the Bengal nawabs asserted their power and autonomy. Through the eighteenth century, the conflicts between them and the East India Company intensified. The nawabs refused to grant the Company concessions, demanded large tributes, denied it the right to mint coins, and stopped it from extending its fortifications. They claimed that the Company was depriving the Bengal government of huge amounts of revenue, and also undermining their authority by refusing to pay taxes, writing disrespectful letters, and humiliating them and their officials.
On the other hand, the Company declared that its trade was getting ruined because of the unjust demands of the local officials. It believed that trade could only flourish if the duties were removed. To expand trade, it wanted to enlarge its settlements, buy up villages, and rebuild its forts.