a. Most if not all Ramp dragon netdecks run two at most lightning blasts, since Nep and Seraph aren't as prevalent any more. b. 3 Mords and 2 Neps, Because when you're outta lightning blasts and theres a Mord on board and Khawys hiding in their deck ready for free heals then things can get a little dicey.
In short Nep adapted to the meta, so think of a deck that you've been wanting to play and think to yourself,
"If I was playing ramp dragon what would what I not want him to have" though balancing this is important, since tech too hard against dragon and you get shit stomped by everything. 3. I don't play dragon so~