The Prancing Seahorse:
As scalla said, you need to find the vegetables. Check the doors in The Prancing Seahorse for ideas as to where they may be.
Sir Gula's House:
You cannot get in until you have completed side quest An Appetite for Murder.
Chains on the walls/side quest Rune Handles:
There are 5 in total. Rough locations are: 2 on Lanilor Lane, 2 in Crows Nest, and 1 that is the biggest pain in the ars in to find in the Market which will really annoy you once you find it.
Good luck (^_^)
