RE: 1600 pts - flaming Vampires v Skavens. Suggestions ?
Here are some suggestions. I virtually always play against the dreaded Ratmen, so I have some experience:
1) You will almost definitely see a Grey Seer. A lvl 4 caster right out of the bag is hard to resist, especially at over 1.5k. If you don't see one, then lucky you I suppose. But either way, I think your Combat-oriented Vampire Lord is going to be outclassed by a Grey Seer. I would rather see a tooled-out Magic Vampire Lord in your list. Close Combat Lords can be tempting, especially now that we have the +2/3 attack swords from the BRB, which are just gravy when combined with Red Fury. But the rest of your army will suffer for it. You need a lvl 3 caster at least, and maybe a Lvl 4, although you likely wouldn't have enough points for MotBA if you do that.
2) No Great Weapons on the GG? This may actually work because the Skaven have been known to come at people with large hordes of cheap, weak infantry in the past, but S6 is still great. It will completely cancel out a Clanrat's Armor Save, and it will wound both them and Plague Monks on 2's. I would go GW's if you can scrounge the points.
3) You may want to field your Ghoul units as a horde. 2x23 units won't really hold their own against a 40-50 man Clanrat horde. With a Caster Lord, you MAY just be able to keep them alive with enough SuH and IoN, but I wouldn't count on it. Go Horde for survivability.
4) This is more of a tactics suggestion. You need to keep your Blood Knights screened from missile fire at all costs. Virtually everything in the Skaven army can simply buy Slings to gain shooting. Plus, they have several annoying options for ranged attacks. I always field a KoBK unit with the Flag of the Blood Keep when I take them to protect against such things, but you don't really have the points for it. Just keep them behind terrain for as long as possible, and get them stuck into combat fast. If you don't, they will suffer the consequences.
Well, that's my 2 cents. Hope this helps, and I certainly wish you luck against the rats.