If I were to take the Cross Blooded Archetype from the Ultimate Magic and choose the sage and draconic bloodline would I still be able to take the Dragon Disciple Prestige class?
Yes you can take the DD prestige class. Its even legal to do so in PFS. But..
You may have trouble convincing your DM to advance the draconic bloodline but it might technically be allowed under the rules.
If interpreted the way I read it I would still gain my bonuses to the bloodline but I would lose the ability to choose between sage and Draconic. I would be required to choose the Draconic bloodline for the number of levels spent on DD but when/id I go back to sorcerer levels I would then be able to choose either of the two classes. But that's just my interpretation of it and would obviously need to check with my DM.
i think that is totally reasonable, especially if the DD scaling only applies to Draconic BL powers, not Sage in this case.
but the Sage Arcana would still modify ALL powers to use INT not CHA.
you should still be able to take DD even if you don't have Draconic Claws, albeit if you don't you won't be able to use the DD bite or have it's elemental damage kick in (even if you have claws from another source, it only applies to Draconic BL claws). that latter bit also applies if you want to go wildblooded:linnorn and go into DD, you still qualify since you still have the Draconic BL (even it's powers have been modified), but the claw thing doesn't work.
if you don't have levels of sorceror (i.e. you went bard or summoner) then DD grants you the bloodline powers, including draconic BL claws... but that's not what's being discussed here.
if you DO have sorc levels, then it doesn't grant you those powers, it just stacks with what you already have, if your archetypes removed claws at 1st level, DD isn't going to give you them back. nowhere does it mention granting claws, much less connected to CHA. the form of dragon SLAs of course have claws, but those are not sufficient to trigger Dragon Bite which requires "us[ing] his bloodline to grow claws" and Form of the Dragon is not a bloodline feature, but a feature of the PrC. a bit overly restrictive IMHO, at least Form of the Dragon should count (which helps with rounds/day even for people who do have the draconic claw BL feature), but by RAW it doesn't work to trigger Dragon Bite(/Elemental Dmg) and definitely doesn't grant you the Draconic Claws 3+CHA rounds/day ala vanilla Draconic BL.
The linnorm breath weapon wouldn't count as claws for the dragon bite power, but you don't need the dragon bite power if you have a bite attack anyway. Is there any other place this matters?
you can't crossblooded sage.
He literally wrote that he knows, but doesn't care:
I take Crossblooded arguing that Wildblooded I believe was never meant to count as an archtype just more options for a sorcerer. Crossblooded gives a lot of restrictions to start and now to say oh no you can't make them wildblooded is %*&%&^%.
Besides, per RAW you can anyway by drinking an Ampoule of False Blood.
as far as Ampoule of False Blood goes i don't believe you can pick archetypes for magic item creation and wildblooded bloodlines are archetypes per raw.
Bloodlines are bloodlines. You buy the item, drink it, done.
And I also agree with Derek Dalton: Wildblooded was meant as more options, not as some quackjob-archetype.
I don't comment on it further here. This's a necro'd thread, and then having an issue brought in that the necro-op consciously & purposefully dismissed in his very first post.