Nope, bass. Does JP even have/use a baritone guitar?
Yes and he uses it in blind faith.
But, you are correct, the intro riff is on the bass.
Yes and no. It's kinda tricky and I'll try to shed some light on this. Here's a note from the first page of Blind Faith's transcription in the Warner Brothers Publications
Authentic GUITAR-TAB Edition book for Six Degrees of Inner Turbulence:
On this song John Petrucci uses a Silhouette Bass which is played like a standard six-string guitar tuned down 3 1/2 steps.
And here's what Ernie Ball's Music Man Silhouette Bass looks like:
It's a very grey-area thing and arguements can be made as to whether it's closer to being a bass or baritone guitar but these conflicting specs make it hard to credibly label it as either of the two:
Scale: 29 5/8" (75.5 cm) which is definitely more akin to baritones than basses.
String gauge: Variable but based on the lowness of the tuning JP uses, his string gauge would be leaning toward gauges more commonly associated with bass.
Overall look and setup: Far more similar to a baritone than a traditional bass from the guitar-centric string spacing to the pickups to the string saddles and neck width.