And if he wins as an "Independent" then do the Dems have one less seat in the Senate?
no, he would still vote with the Dems.
Even tho Lieberman would caucus with the Dems, in terms of majority and/or majority/minority ratios for Committees, it'd still be one less (official) Dem, wouldn't it ? I wonder how that would work in a worst case scenario if the GOP lost several seats in November.
With the retirement of Jumpin Jim Jeffords, under the "Lieberman wins as an independent" scenario, would he then be the only Independent?
Only on a few issues, as he will vote with them on most issues.