Your opening rotation looks fine, except that I wouldn't pop VB immediately. Wait a few seconds to see what your incoming damage is like. Also, having Bone Shield up will soften the first 6-7 seconds of the pull, and overlapping cooldowns is usually a bad idea.
IBF shouldn't be used as liberally as your other cooldowns, but is still a great mitigation tool - I wouldn't save it for dire emergencies, because then you'll never use it, but rather for a) predictable spikes in damage (if a boss soft-enrages, or something like that dude in Grim Batol who does 100% extra physical damage when you kill the add on top of him), or b) just regular old pulls where you run out of cooldowns but still need the mitigation.
DRW is interesting, it is both a good way to avoid physical damage (for example, if a boss has a soft enrage that increases his auto-attack damage), and with the glyph is good for threat if you have enough RP or runes to continue your rotation without much downtime. It takes some practice keeping an eye on your rune cooldowns and RP (something I am still working on), but with such a short cooldown it should be available much of the time. I use it rather liberally, either to avoid physical damage, or for securing threat/putting out addition damage (this is especially nice in conjunction with Empowered Rune Weapon, too bad that's on a 5 min cd!).
Yes, that's exactly what he means about Bone Shield. It's a good ability, obviously not as strong as some of our other cooldowns, but being able to use it before combat to soften the beginning damage is great to give your healers time to get into position, etc.
Obviously, you have several DPS pieces to replace, especially those boots. (the belt is okay) http://www.wowhead.com/item=66909 can be obtained as a quest reward in normal Lost City, and one of the bosses there also drops http://www.wowhead.com/item=55873 which would be a nice upgrade to your DPS ring. I"d recommend heading in there before you get to Heroics.