Best db setup to accomplish yes/no list of clients for daily calls
Sounds like you need a proper CRM  (:
For the days of the week I think you have it right, have a column for each day of the week and if a day is a "no call day" you check it off.  Your query would then say, "ok it's Monday who can I call?".

As far as the adhoc days (on vacation etc).  You may just want to have a notes field that shows on each record on the call list.  This can be reviewed before calling and modified or skipped based on the content of the note.