what is the status of gold and gift giving in the poem? who gives gifts, who receives them and why? are the modern concepts of wealth, payment, monetary worth and greed appropriate for the world of Beowulf?

Gold and other valuables are given to Kings and war heroes by both subjects and underlings. Yes all your mentioned items were part of Beowulf's world. Beowulf himself inherited King Hrothgar's throne by killing Grendel and his mother. Before dying, after slaying the dragon, Beowulf wanted to be covered with dragon gold.

no