Vaccinating for CL is only recommended for herds that already have an infected animal because once vaccinated they will always test positive for CL. In addition to that, it's not a guarantee against the animal getting infected with CL. Most breeders (including myself) do not vaccinate, so nothing to worry about with that.
I would ask for negative CL, CAE, and Johnes tests (aka the Caprine Biosecurity Screen at WADDL). She should let you pull that test prior to/as a contingency of sale if she doesn't have recent results herself.
A quart a day isn't busting the bucket, but it's not terrible. Was that as a FF?
Here are some things I try to ask and look for:
Has she ever had trouble kidding? Is she a good mother?
What is her personality like? (The first two does I bought were wild as March hares. Never again!)
What are her ancestors and siblings like? Are they consistently good producers, easy kidders, good conformation, etc?
And I'd also look up USDA milk test data on her and her dam and other close relatives if possible. That can be done through ADGA Genetics if she's ADGA registered.
I hestitate to comment on conformation because I'm no expert and also, it's hard to tell much on a fuzzy, unposed goat.