Imo, you should finish what's in the tool already, properly tweak things then move on bigger things. And i agree the next big one is the spell editor.
Just a spell editor, something that parse the .txt files and return the values to a window (with tabs like item editor) for editing purpose.
Quest editor, for me, it doesn't matter. I'm still using notepad to write the quests and like it that way. But about your question, if the user was able to enter the correct info for the program to connect to the db they should be able to point to the quest directory correctly.
And i use your program, everyday! Good job again.