Honey dries out the beer, and it may or may not add any flavor, depending on florals from the varietal.
Is this a 5 gallon batch? 3 lbs is a TON already. This is going to be a dry, dry beer, and again, may or may not have any honey character. Honey itself is all simple sugars, so it ferments out almost completely, and all that's left is the florals that the bees used to make the honey, which is tough to control and keep consistent. Most brewers use honey MALT instead of actual honey because it is a much much more consistent produc.
1lb of honey is about the average that most people will add to a 5 gallon batch to get a prominent flavor. 0.5-1.0 lbs of honey malt will accomplish about the same thing, with much more consistency.
As far as priming with honey, I wouldn't. First off, you already have way too much in this batch, and second, there's not much advantage to be had. You are basically asking if you should prime with sugar that cost $5 a pound or sugar that cost $1 a pound.
Prime with the cheapest simple sugar you can realistically control. The only reason most people use priming sugar instead of grain sugar is it is just a bit easier to work with even though it's a tad more expensive. No reason to prime with honey, though. Tougher to measure and way more expensive.
Good luck!