I like the way you think. For example, I also associate the need to drink blood with an attempt to stabilize aging. Even if it doesn't really help, the lady in the hat may think it does. It is no accident that in folklore, blood for vampires was not only a means of food, but also a means of rejuvenation. Even in real life, the same Bathory took a bath of blood to preserve her youth. In other words, such a concept exists and can find a place in the game.
About Alex's face, there are these thoughts: in the bad ending of Revelations 2, we can see that along with Alex's consciousness, Natalia also has awesome physical abilities. Judging by the red eyes, Natalia is an adapter of a virus that can be controlled by Alex's consciousness. Therefore, I suspect that Alex's mind could also "correct" Natalia's body and face, using the evolutionary capabilities of the virus. This theory makes sense, since the influence of the Progenitor virus on evolution has been discussed more than once, and the influence of consciousness on the development of the virus was confirmed by Albert after the storyline of Vladimir.
I can also agree that the castle did not belong to Spencer, although I still believe otherwise. The castle is definitely very old — much older than Umbrella, so the Umbrella symbol is hardly an umbrella. It's probably a cross. Since we can find similar symbols in the Spencer mansion, although they may have been there before the corporation was founded, I thought it might be the Spencer family cross.
But it can also be a symbol of the order. The trailer repeatedly refers to Vlad Basarab, so this symbol may be an allusion to the Order of the Dragon, in which Vlad's family took part (the dragon is Dracul (Vlad II was Dracul), and Dracula is the son of the dragon). Since we can see the image of the Devil on the castle gate (which also means Dracul, since the images of the Devil and the Dragon are often intertwined), I believe it's all connected.
In that case, Spenser didn't have to steal anything if his family was related to the order.