Making supports more skill based and rewarding

Recently someone mentioned how you remember Lulu saving someone with her R, but not just clicking E on someone as Janna. That made me think, heals and shields should be much more exclusive, but more powerful.

In other games I have seen, healers are their own main category in that you want to have a healer. Not a support, a healer. I think to make team play more demanded, self healing should be toned down greatly, and more champions should have their healer base pushed. For example Soraka or Sona should be desired for their healing because if not, your team lacks sustain. Right now Marksmen can get 20% life steal with just Bloodline and Bork. I play a lot of AD, and I can tell you it's pretty insane. Especially if the enemy has no tanks so I can afford to get a BT as well, since I don't need armor pen and I end up with 40% life steal on top of crit.

Shield supports like Lulu and Janna should also be made more about timing. Lulu' s shield lasts 6 seconds with a 10 second cooldown. At 40% CDR you can perma shield someone. That's insane to me. Shields should either have much longer cooldowns to be more in line with heals, with more temporary health as opposed to smaller, permanently returned health. If shields won't get higher cooldown, they should last a fraction of the time. Say a 300 health shield buy only for 1.5 or 2 seconds. An example of that in an FPS would be Zarya from Overwatch. She can shield an ally for about 300 health for 2 seconds or so. A very short, but very clutch ability that feels rewarding to use well.

Making shields more windowed and heals more needed, would increase the need, and skill needed to play support, without making carries, marksmen or otherwise too hard to kill.

If you lack a healer, it rewards more beefy comps like juggernauts as a carry with say warmogs as the enemy is punished for not having a healer. Or if you choose to have a healer you choose to give up damage in your comp by not having full AP Lux support, in return for being able to protect your carries and make them more durable.

TLDR: Nerf life steal and self sustain, make healers more of their own required subclass rather than "enchanter that happens to have a heal." Nerf shields so you can't spam them on carries, with shorter durations.