In a game started after installing the 1.34
patch, Finnigan will have a fairly good inventory, selling lockpicks, traps, potions (at least poison, IIRC) and miscellaneous equipment. Also in this case you can return the magic lockpicks he asks you to steal to complete the quest, then buy them back.
In games started with the unpatched version, or an earlier hotfix, he does not carry much, and returning the magic lockpicks is final (it is better not to complete the quest, IMNSHO).
BD is the same as DD, only different. <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" /> There are a lot of similarities, though the skill system has been changed and character movement / management is a little different with 2 characters to control. BD is a bit more linear, being divided into separate acts, but after the first act it is fairly non-linear within an act.