Since it's blatantly clear I'm a VF fan and therefore obviously biased, I'm not really going to try hard to argue against these points. What I will point out though is that the character models do appear to have been remade for this game. Just compare how they look in DOA5 and VF5 and you'll see a big difference. So, as far as how the VF characters look (sans animation) they have been made to fit with the general aesthetic of DOA5. I really don't think you can say their proportions are off. Just as an example, I think Sarah looks skinnier in VF5 than in DOA5, and Jacky seems to use the same generic male body model as other male fighters (maybe Akira too). At the very least they finally look as good as the renders used in the VF5 character selection.
I'll give you the old voice clips, they probably could have hired new VAs. For some reason though I have a hard time seeing what you guys see about the differences in animations, and believe me, I'm trying. I kind of see what you mean, but to me it's such a minuscule difference. Maybe because I played VF a lot more than DOA, I don't know. I just know that it's something I never would have noticed unless pointed out. I think the characters in both series each has distinct kinds of movements. When you say the VF characters lack animation points, then okay, I can understand that, it's just not a big deal for me, at all. I guess the closest analogy I can think of is if Street Fighter III character sprites were slapped into BlazBlue, but I don't think it's that bad.
Really though, as far as guest fighters go, I think the VFers "fit" better than almost every other guest fighter. You had Yoda,Vader, Spawn, and Link in SoulCalibur, Scorpion in Injustice, Predator in Mortal Kombat now, and Spartan in DOA4. Ezio in SC5 was one of the better choices. On both an aesthetic and thematic level, I don't think many fighting games go together much better than VF and DOA, except maybe Street Fighter and King of Fighters. I guess you can fault the developers for not doing more to make them mesh better aside from new character models, but I think that they were able to basically import them shows how compatible they already are with DOA. New recordings and a little work on the animations plus the new models are ALL that's needed. Hell, I even noticed some moves from VF4 used for their holds, so Team Ninja did that work too as a nice touch for VF fans.
I know that there are some people unfamiliar enough with both series that they can't tell that Akira, Pai, Sarah, and Jacky aren't even DOA characters. Seriously, I think Rachel stands out more than they do, at least when compared to the rest of the cast. The VFers look a lot more relatively normal than she does (as far as default costumes), and I feel like she breaks my immersion more than any other character. Point is, I don't think you can say that stiffer animations and dated voice clips are nearly as bad as Kilik fighting Yoda in a German castle when it comes to breaking immersion. There's stuff that's much harder to tune out, and at least all the VFers fit as "normal human martial artists," and aren't something like super heroes or aliens or demons or super soldiers.