It should be slightly below, approx. 1/8" the bowl gasket mating surface. An old trick from the automotive days working on Holley 4 BBL carburetors, it is not too critical of an adjustment.
Save your money and fix the CV you have. If you need a seat let me know and I'll give you a link.
Also never "assume" the dealer did what they billed you for or done under warranty either.:s
it might be worth changing the float needle again as you may have a bad one now the rubber coating on the tip of the needle is easily damaged and can harden with age (just cos its newly fitted doesn't mean its a good one)
and the problems started after it was fitted id go back there again
the level in the float bowl should be below the top edge of the float bowl
approx 3/4 full
if you get frustrated enough to change the carb don't dismiss the mikuni hsr42as i found it works well for me and doesn't ice up the same in the early months of the year (its on the 92 softail) yet the 93 Sportster and 94 Dyna work OK with the standard CV a wee bit of icing on the Dyna
hope this helps
Brian