1. You cannot. DCTC automatically closes this kind of connection after 30 seconds.
2. the usage of -b command line option does not allow you to discard the / of the /LOG command, that's why the command is ignored.
About configuration file, In one word: never. DCTC is not made to perform this task. This is the job of a UI. dc_gui makes this quite well :)
A last word to conclude, if you want to have fast replies, avoid this list because I only check it when I post new release. There is a mailing list you can find on DCTC homepage.