Yes VoG was available in Vanilla, but apparently, (seen here), The Taken King is on sale for Xbox live gold members, it is definitely worth picking up!
If believe there is a cap on damage dealt/taken (not entirely sure on this) so being Max Light is not really a necessity. However, if there are 4 of you being relatively inexperienced, then being at the recommended light will make things a fairly intense challenge.
As for doing it with 4 people, here are the sections:
Building the Spire:- One person on each plate, the surplus on the middle/top plate. The middle two guys have it a little easy here, and can offer support to the two side plates when the call out.
Confluxes:- All 4 protect the first conflux, easy peasy. Split in to two for the left and right conflux phase, should be fairly straight forward. Then split one on each conflux for when all three are there, have one sweeping, offering help (maybe a nice roaming super like Boltcaster or Sunbreaker) to help when things get rough for any of the confluxes. Alternatively, you could have one up on the top platform, overseeing everything with Icebreaker.
Oracles:- This will be a tough challenge, cheesing from the back will be difficult with so few people, so you will have to roam around the arena, clearing up the oracles as they spawn, dealing with the adds, and shooting down the Hobgoblins that spawn. This will be difficult, but at higher light, this should be very doable, if you are organised, and use all in your arsenal to wipe the oracles and adds as quickly as possible.
Templar:- Very simple. One with relic, 3 on DPS duty. Gather on the right hand side, leave the harpys for the relic holder, shoot the oracles you can easily get to, gather up and cleanse for those that would be difficult to get. Taking down the Templar once the shields are gone should be very simple with high DPS weapons such as, Touch of Malice, Black Spindle, Sleeper Sim etc.
Gorgons:- Easy if you know the way, soloable if only one of you do, just have the other rejoin if you lose patience guiding them through.
Jumping Puzzle: With exotics like Bones of Eao, and Twighlight Garrison, this should be even more of a breeze than ever.
Gatekeeper:- Exotics such as Celestial Nighthawk make soloing one of the portals a breeze, run through, pop golden gun, take relic, get the hell out. Using Year 1 weapons like Gally will still work a treat, and Year 2 weapons should still make going into the portals solo pretty simple. Have one protecting each plate from Praetorians with a decent shotty, and you will be able to breeze into the middle to protect the conflux. Two relic holders on the portal, other two at the top killing the spawning Minotaurs.
Atheon:- Three will be teleported, one will remain to kill the Supplicants, just look on the radar for which way they have been teleported, jump on the platform in the middle of the plate, and shoot as many as possible. DPSing Atheon should be a breeze!
Good luck!