I'm guessing he didn't use the Vampire Killer because of the whole "it drains your life if your last name isn't belmont" thing.
That could be one rationalization, but if you're going to adapt "
Dracula" to Castlevania then why wouldn't you have him wield it?
After all people complain that at first the series was very specific about the Vampire Killer being needed to kill Dracula and that in the later filler games any schmuck with a sword can do it.
So as long as we're discussing changes in the series, this is one point I would contend.
Only a Belmont with the Vampire Killer or someone wielding Dracula's own power (Alucard) can put him down for the 100 years.
So, in game play, I would make it so in CV3 Sypha and Grant can't damage Dracula when he reaches 1 HP.
Same for Maria in RoB and Charlotte in PoR.
Eric get's a pass since he's using the Alucard Spear. Maybe add some exposition about the spear being forged with Dracula's magic.
I've already explained how CotM should be rewritten and modified to remove Dracula and have it fit in with the timeline.
I don't think you could salvage CV64/LoD without a complete rewrite, a new time frame, and game play changes.
And no mention of him being a widower isn't the same as him not being one. I'm sure he mentioned that to Lucy when proposing to her, not in a guilt-trippy way, but in a "I have a son who needs a mother" kind of way. We only hear about the proposal secondhand in a letter she writes, and she probably didn't feel it necessary to mention details like that to Mina.
That is true enough, but it is definitely a point that should be stated for clarity and better consistency if nothing else.