Well, I watched the final two episodes last night. I really liked the finale. And the final battle with EVERYBODY in it was really, really good.
I'm fine with the characters' ends for the most part. Not everyone got a big send-off "moment" like Vanessa, but it seems like we left them in good enough places where we can kind of imagine where they go and what they do next.
And I agree with you about the new characters. Generally it seems like shows add a bunch of random new characters in their final seasons and they suck. In the case of Penny Dreadful, I loved all the new characters this season, especially Dr. Seward and Catriona. I would watch a spin-off just about Dr. Seward. Such a kick-ass character. I loved her "Fuck him" line about Dracula and laughed out loud.
My main problem with this season (aside from it being over) is that it feels like, because Logan knew this was the end, he tried to cram so much stuff into these 9 episodes. It feels like we could've
easily gotten two or three seasons from the material that was in Season 3.
I also feel that enough time wasn't given to Dracula's attempted courting of Vanessa and the aftermath of that; the whole "end of days" thing in the final couple episodes EASILY could have stretched out half a season. Just think how awesome that would be. End of Season 3, the final scene is Vanessa getting bitten by Dracula. Then all of Season 4 (instead of the last two episodes of Season 3) is assembling everyone to save her, just like they did with Mina.
Like I said before, the splitting up of the characters didn't really work for me. Though it may have had everything not felt as rushed.
So, though I'm sad it's over, I'm fairly satisfied with the end we got for the characters.
Also, this made me laugh:
https://www.gofundme.com/2b2r9qxw