Check out this thread for some Intimidate DCs:
http://forums.ddo.com/showthread.php?t=245254. As it stands you probably could do VoD hard or DQ elite without much problem.
If you took Armor/Tower Shield Fighter Mastery you could also get a few more DEX points on your AC. Not sure how pushed your AP layout is like though.
Personally I think using the cloak slot only for +5 resists is a difficult cost. At the moment I actually use Light and Darkness, and don't bother too much with in TWF mode. I'm planning to have the +5 resists on my DT, also I find a shield wand very handy when in TWF mode.
I've found 60-70 a steady AC for tanking VOD.