There are no good AD item options for support. Ashe herself is perfectly fine, there's just a nonexistent support build path. I guess you could play her as a second ADC, but between Sightstone setting her behind, not getting farm and being the most expensive item path in the game, it'd be a long time before she does anything.
Probably just needs some small buffs. He used to get played a lot more, both jungle and support, but several nerfs in the past year has made him fall out of favor.
A lot of her power is in her scaling. This is not ideal for supports champs who have oft rely on base stats due to a low income making item purchases difficult.
A melee support without a form of hard CC, but I'm not sure if there's any room for buffs without risking Kog'Maw becoming too strong.
This is the weakest support in the game hands down, even weaker than Taric, patch 4.13 completely ruined her. Everything she can do, AT LEAST 2/3 of the other supports in the game can do better and both Nami and Bard are on every last one of those lists. Her kit can't work, she will never be fixed without a revert, partial revert or re-rework.
His only damage source is a skillshot, his abilities all got nerfed and his reset doesn't work on ult anymore. There are a lot of places that can be fixed and it'll take at least a few of them to make him work.