While some of your points are sound, SMN Really only has 2 options outside of Avatars.
A) Being a gimp Healer. (Face it, Don't lie. Cure IV is gimp, even with 50% Cure potency, Its gimp, and it raises a lot of Enmity).
B) Or Being a Mediocre Melee.
When I'm faced with 2 Options, I chose the one that most productive to my time. If I'm in a party as SMN for whatever reason, and theres also a WHM in my party, I'm chosing Option B, Melee. If i'm The only healer in the party (Which in itself would be absolutely stupid if you're fighting anything stronger than a Land Worm), I'll default to my Gimp healing Abilities.
I have gear for both, I come prepared for both aspects.
Theres obviously situations for everything, But as Mediocre as SMN melee is, Its more productive than sicking your avatar then picking your nose hoping your WHM slips up on their cure duties so you can spend some MP. SMN Melee, Especially in Abyssea where you can stock up on DD Atmas (For Predator Claws) is not awful.
When you get to the bare bones, If your WHM is worth a spit, and for whatever reason You're there on SMN, Your better off Meleeing with your pet if you have a proper build.
Of course its not for Every NM (*Hint: Ones with multiple annoying TP moves where your TP Feed would get in the way), But for some fights, in some situations, Its useful.
Limited though it may be, the Idea is sound. It lacks Frontline Traits yes, But it does not erase the notion of it being able to Melee. WHM lacks any front-line Job Trait, (Maybe aside From afflatus Misery but if that counts so does Garuda's Hastega, Ifrit's Crimson Howl, Etc), But WHM melee is fun/has some places (Limited as it may be).