Vampiir spec tipsFollow

You'll want 43 Pierce for sure, since Vampiiric Feint -> Eyeshot is your best attack chain (Lung Shot and Knee Cap do the same damage as Eye Shot so only go that high if you spec Dementia for the armor debuff, and Dementia is better for high-RR vamps). 50 Shadow Mastery is great for PvE but for RvR you'll probably prefer 38 SM / 32 VE so you can get the fumble debuff (or 32 SM / 38 VE if you want the top stealth detection, but I'd rather have the 2nd best HoT personally).

As for floating, vamps do that automatically at around sprint speed, regardless of how they get there. So you'll float any time you use the speed spell from Shadow Mastery, sprint, are under the effect of bard speed, etc... but only while moving.