I am making bourbon chicken. Can I boil down the marinade to use as a basting sauce and a place to park the cooked chicken?

First, if you're using the marinade to serve the chicken, boil it down very well. Raw chicken juices are no one's friend! But I think I'd store the chicken separately from the marinade. (Well wrapped, it should be fine.) Depending on its ingredients - especially acidic ones - a marinade can break down meat fiber and effect its texture. You can use the boiled down marinade as a glaze to drizzle over the chicken when you serve it.