Hello. I'm aware you can become a vampire lord at two or three points in the quest line, regardless of which faction you choose. Since siding with the vampires means no upgraded crossbows, I want to join them, but I also want to be a vampire lord. I hear Serena will join as a follower and I can ask her to turn me into a Vampire Lord. So I have few questions:

After joining the Dawnguard faction:

1. Will Serena still give me the option to turn into a Vampire Lord?

2. If I become a Vampire Lord through Serena, will the Dawnguard still accept me and allow me to use their weapons, armor and trolls

3. Would I still be able to gain all the benefits (perks and equipment) to a Vampire Lord even if I joined the Dawnguard all the way through.

4. Can I still have the castle as my home somehow even if I'm not factioned with the vampires?

No, after a certain point in the questline you cannot be a vampire and be in the Dawnguard at the same time.

You can however get Serana to turn you once the questline is finished.

When the Dawnguard questline is finnished you can be a vampire lord but the dawnguard tell you to cure yourself before being able to do any misc quests.

Awesome Can I still make/use crossbows and can I still get all the equipment for vampirelord?

You cant be a vampire when wanting to do dawnguard 'faction' quests.