Just some added confirmation/help:
In the Codex: Eye of Terror
FAQ (available at
http://uk.games-workshop.com/news/errata/3/), it states:
"Some units from Codex: Chaos Space Marines have special rules that apply to "chaos" units, such as a Word Bearers Dark Apostle with the Demagogue Ability or the Dirge Caster vehicle upgrade. These rules also apply to all units drawn from the Lost and the Damed army list."
and...
"Allied Chaos Space Marine units that are drawn from the Troops or Fast Attack sections of Codex: Chaos Space Marines are coutned as Elites when taken as allies in a Lost and the Damned army if they are given a Mark of Chaos. Allies drawn from the Codex: Chaos Space Marines
HQ and Elite sections and that are given a Mark of Chaos remain in their respective category when taken as allies."
For your last question, the
FAQ does not cover that, but I am almost positive that it would use Chaos Space Marine vehicle upgrades.