So yeah its a tiny quest but the completionist in me is fuming. Im on ps4 and Svari in solitude asks me to talk to Greta and get her to go to the temple, and Greta asks for Roggvirs talos amulet in turn but I had looted Roggvir at his execution so when I tell her I already have it and I don't need to loot his coffin, she thanks me but the quest doesn't complete, I dont get a reward and the quest doesnt dissapear from my log.

Also I cannot give Ystolda her wedding ring back in "A night to remember" and the tree in whiterun is bugged after I did "The blessings of nature". The gildergreen sapling is now in centre but the old dead tree didnt dissapear, the sapling is just clipped inside it

Standard Glitch, and feature not a glitch.

Go back to a save prior to the execution. Don't take the medalion, until asked. (Many such avoidences in the game.) Be leary of any "Named" odd item you come across. In your first play take them all. When you note which are glitched it makes it easier in the Second Play through.

The tree is normal.