There are already many threads discussing recommendations to fix gravity, some of which are still on the first page of the forum. The proposal to convert Propel to a cone has been voiced in those threads many times. There is no particular reason another thread is needed.
That said, there is absolutely no way that Propel as a cone keeps the same 1.96 damage scale. Nightfall is 1.10. Energy Torrent is 0.96. Frost Breath is 1.40. Electron Haze is 1.35. You're looking at a 30-40% reduction in damage, as well as a substantial increase in recharge (my guess would be to 16-32 seconds). That's assuming that the devs would give a control primary a non-controlling cone attack when they're already available in the ancillary pools.
I'd be fine with a reduction in damage if it was made a cone attack 
I might even pick it up then.
Spines/ D A lvl 50 Scrap, stone/wm lvl 50 tank, Kat/reg lvl 50 Scrap
Grav/Kin lvl 50 Cont, Fire/Enegry lvl 50 Blast
Warshade lvl 50, PB lvl 39, nightwidow lvl 50, crab lvl 42
plant/thorns lvl 50 dom, ice/fire lvl 40 dom, grav/nrg lvl 41 dom
Propel becoming a cone would not really fix anything for Gravity.
It would still lack AoE Control and damage. My opinion is that propel is fine except the animation time. It is lift and dimension shift which are the best candidates for change.
I agree with Uun though, try and keep the Gravity posts into one of the already existing threads.
Gravity has been one of those sets that's underperforming. Supposedly its a higher damage set, much like fire. The numbers don't bare that out. Its pet is low damage/high control. All the damage it does have is smashing damage which is highly resisted.
Gravity is an interesting set. Wormhole by itself is such a unique power that many people will play the set just for wormhole. But wormhole isn't enough to make the set perform quickly.
Gravity's signature visual power Propel underperforms to the point that many people don't take it or they respec out of it later.
Its fairly high damage, but it takes a ton of time for the animation to occur. There in lies the problem. On teams you are throwing forklifts at dead targets.
I think the easiest fix is to make the attack a fairly narrow cone like Nightfall. Keep the damage about the same or up it. And then otherwise leave it alone, recharge and endurance use. Just leave it alone. Gravity is under performing now. I think this would fix it.