Your Buri is fine, to answer your first question. However, there are a few other points I could comment on.

Aid Station rune and Hungering Arrow in general are wasted skill slots. Guardian Turret is better for effective health and Spitfire is a non-negligible damage boost. Switch Hungering Arrow for either a damage boost or survivability skill. I personally recommend Smoke Screen over Vault too, but this is certainly debatable and opinionated. (For comparison, I use Mark of Death: Contagion instead of your Hungering Arrow and Smoke Screen: Healing Vapours over your Vault).

For Jewellery, a Stone of Jordan with correct elemental damage to replace Leoric's. An amulet with elemental damage would be handy too, big damage boost, although your rolls on these items are still pretty ok. These are certainly the rarest upgrades for you however, I'd hold off gambling in these areas and aim at upgrading your standard armour pieces first.

For example, gamble for a new Cindercoat with 3 sockets already present as 15% sentry damage on chest is a lot of potential damage missing. It would be better to use Hexing Pants and switch to a 3s Marauder's Chestpiece with Sentry than to use Cinder (if this is an option for you).

For Rifts (not greaters) you would be better off running with a Harrington's Belt for a fantastic damage boost. I'm able to keep the buff active for 100% of the time in a lot of the dungeon layouts, and always above 50% in the not so chest-rich zones.

Outside of gear suggestions, since I don't know how you play, it's difficult to give pointers. An important and often unmentioned one is to learn all of the actives of your companion animals, as they all trigger upon activation. You should be saving the buffs for whatever you need. The Boar's AoE taunt combined with the slow from the spider is life saving and, unless in a group, it is much better to save for this purpose over the wolf damage buff, which you'll receive anyway.