Deathfire Touch needs Buffs still, and ideas for new keystones?

Mainly want this post to be about deathfire touch. It essentially has zero impact when really far ahead. and I mean REALLY far ahead.

First off let's look at what deathfire touch is:

Dealing ability damage to enemy champions applies a bleed, dealing 1 (+ 3.125% AP) (+ 7.5% bonus AD) magic damage every half-second for a duration based on their type. Single Target: 4 seconds for a total of 8 (+ 25% AP) (+ 60% bonus AD) magic damage. Area of effect: 2 seconds for a total of 4 (+ 12.5% AP) (+ 30% bonus AD) magic damage. Damage over time: 1 second for a total of 2 (+ 6.25% AP) (+ 15% bonus AD) magic damage.

Clearly, as keystones are focused around a playstyle, this playstyle is a poke centric keystone. It is focused on adding the most damage to champions who mostly poke down their enemy laner rather than try to chunk them with a few rotations of spells. It has NO cooldown, so as long as you aren't refreshing the keystone by procing an ability right after another, it should in theory be more efficient than say a keystone like thunderlord's decree.

So why is this not the case?

1.) It's base damage does increase with levels (Thunderlord's decree DOES) 2.) Without a huge amount of items, the keystone does next to no damage even on the best case scenario type of spells. (think Annie Q, Leblanc Q) 3.) there are very few spells that are the best case scenario. most are considered AOE.

I want to say I absolutely love the idea of DFT for poke style champions, but the execution is not so good. Because of its synergy with DOT (even WITH reduction in duration once it ends) the keystone has been kind of set up to be nerfed so certain champions who would abuse it don't get too overpowered. (brand, swain, malzahar, anivia) My suggestion is to not only make it not work on DOT spells altogether, but to give it's base damage some scaling per level. this would make it relevant just TLD is without having to wait for a few items.

My second part of this post is LESS relevant so take it with a grain of salt. I feel we could use some keystones for mages focused around strengthening their utility and as well as sustain.

I would love to see two keystones along the following lines:

1.) Your slows are 20% stronger and your hard CC duration is increased by 15% (numbers can change obviously, but you get the point)

2.) every 4th ability landed on an enemy champion applies 30% spellvamp for that spell.