Venar can spawn in any kobold position, anywhere. I've seen him pop in the tents in the back spawn area, seen him pop in the tents in the center area, and seen him pop two seperate places in the pits area.
He's dropped shimmering terror hide boots for me all ten or so times I've killed him. So, guessing those are his common with the other stuff listed here filling out his loot table.
He's really not the toughest kob in the zone by any means. Has maybe 30 percent more HPs than a prophet/champion, and casts, his MR isn't too much higher than prophets/champs and he can be easily interrupted.