At this point just focus on maxing out their level by beating the story on all of them with help of your daily bounties. There's not much you can do this late into the game just level then up so you can be ready for ROI and just start there you can go back later.

1.There really isn't a fast way to level up your light, you just have to grind it out. I would suggest you level up your factions, you can get a package that has gear or a weapon up to 330 light. You only get packages if you are at rank 3 with a certain faction though.If you have alot of strange coins, you can go see Xur and buy 3 of coins and kill Ultra bosses and use them in the crucible.But since you are more of a PVE player, I would definitely do patrols and do your bounties.You can sometimes get legendary engrams.You can also do the daily heroic mission,I do believe 200 light level is too low to do that.Once you get to a higher light level, that is another option.Right now with your low light level you really don't have too many options. 2.As far as exotics to hold on to, anything goes here.I would hold to your best and most used gear and weapons.For me I have a Hunter and a Warlock so I definately kept my Nothing Manacles,Sunbreakers,The Ram and The Impossible Machines to name a few for my Warlock and Sealed Ahamkara Grasps,Bones Of Eao and Lucky Raspberry for my Hunter.All the weapons and gear your have that isn't year 1 up to this point can be infused. 3.Current Weapons, I can go on and on about that... Patience and Time, Telesto(fusion rifle)Hawksaw(vendor), Longbow Synthesis(sniper),LDR(sniper), etc are great choices.But it depends on which weapons you are currently looking for so those were just examples. 4. I am at light level 335 with both my Hunter and Warlock, so check them out for any other tips that will help you.I am on xbox one as well,I can help if you need it, GT is MootConstant975.