[PTeppic]

Yes, he was capable of the Patronus, but it was after personal tuition. Most of the work he did against Dark Arts was with fairly mild spells, such a disarming, shield and similar charms. However, I guess half the battle is the keeping cool and being able to use simple, effective and fast defensive spells. On that front, yes he's capable (and also of teaching it). But, could he, for example, have attempted the Bubble-Headed charm, or the one used by Krum in the Lake in Goblet? Yes Harry's the hero, but Hermione is perhaps the better magician through greater application of theory; Harry simply has the history of having had to use it first hand (okay, loads of experience). Snape and Voldemort's various summaries are accurate: he's mostly survived his various encounters through luck and help. Only in 5 and 7 do he and his friends have to really fight hard (in 6 they fight but are aided by Felix).