Translation:Even though he is poor, he is happy.
The "o" sound in "pauvre" should be pronounced like "coast", not "cost" (except in Marseilles, maybe)
Because of bien que... It is a conjunction which is using with subjunctive and which is about subjectivity
I'd imagine that bien que is an expression that triggers the subjunctive, like how "though" in archaic English triggers the subjunctive. Shakespere says: "Murder, though it have no tongue, will speak." (not "has no tongue")