Hi Adam, we recently added data input editors to designer which help a lot with what you are trying to do. Please replace your war with ones found at people.redhat.com/tsurdilo/designer/master (which is where we place the wars with fixed/new features that will make it into 2.1 version). Make sure you clear your browser cache before editing your process after the war upgrade.
Regarding missing attributes, please raise a jBPM Jira (Designer component) and I'll look at it asap.
Hope this helps.