For the same reason that I would not recommend most other raw AP/damage items, Morellonomicon leaves you squishy and compromises your role as a tank. The grievous wounds itself isn't strong enough to justify the purchase (especially when Bramble Vest and Thornmail are viable alternatives) and if you just want damage Liandry's Torment is generally far more effective than Morellonomicon. Regardless, if you're already hyper fed or just messing around with your friends, there's certainly nothing wrong with trying it out.

Anyways, thanks for taking the time to come by and write a comment. :^)

Personally, I almost never have any problems against Morgana, although that might just be a side effect of me playing vs. incompetent Morgana playerss. She is undoubtedly a tricky matchup with all her crowd control and the Black Shield which counters your Fling. However, from personal experience Singed is too mobile and can usually dodge her Dark Binding, as it's a slow moving and telegraphed projectile. Along with that, Morgana is very immobile, cannot stop you from engaging onto her team, and her Black Shield has a long cooldown and can be baited out since it only affects 1 champion. Regardless, Morgana is still fairly difficult to lane against and she is definitely good ban if you're having issues vs her, although I think that there are more valuable bans out there.

Anyways, if you do decide to try out Singed support be sure to tell me how it went. Thanks for your comment. :-P

While I have mad respect for Adellaide Skyhart as a player, I personally don't think that Smite is a particularly valuable spell on Singed as a support (not a second jungler!)

Nevertheless, since you're already playing Singed as a support there's certainly nothing wrong with bringing Smite to last hit cannon minions or whatnot

Anyways, I appreciate the comment :-)

While both Teemo and Singed utilize DoT effects fairly efficiently, for the most part you don't want to prioritize damage items on Singed support. Correct me if I'm wrong, but with Teemo it's much more efficient to go straight into itemizing damage (with possibly a bit of survivability mixed in) than it is building tank or utility.

As explained in the guide, Singed's role in a team is to engage and cause havoc within the enemy team's ranks. With that being said, the playstyle mentioned here isn't exactly similar to that of Teemo's. However, if you are looking for points of reference to compare support Singed to, Rakan and Alistar are a good champions to start with. (Although obviously each champion has their own unique kit and playstyle)

Either way, thanks for commenting :^)