A++ Green from me. Bladesinger has always been one my favorite subclasses in the game, and I love the changes.
I've mostly with you, though I'm more neutral to negative on the changes, but they left it mostly intact and that's good enough for me.
Bladework was sorely needed, and now added.
Counterpoint: Bladework is at most a tiny improvement, and can be a trap for players who don't think about it.
With no armor, a bladesinger in the front lines requires Dex for AC. That Dex also feeds a strong save, some skills, and initiative which is important for that first round AoE of choice if appropriate. This really isn't negotiable needing a strong Dex. So if you are using a finesse weapon, you're
at best getting a +1 to hit/damage over Dex, and possibly less. A tiny adjustment.
But it's also a potential trap for a newer player, either because they don't realize how important Dex is and rely on Bladework, or worse they pick a non-finesse weapon. You now have a character who can't effectively melee unless they are using Bladesong, which means, agianst we're talking as a trap for inexperienced players, that they'll either burn them every combat and then find themselves out of them, or they won't and will provide the party a very inconsistant character for building synergy with as they are great at a role and absolutely avoiding that role and it's a bit of a toss-up which will be in play for any particular combat.
So it's at best a small bonus, and at worst a trap. That does not qualify as "sorely needed" in my book.
If you think it's
sorely needed, please address why your INT would be so much more than your DEX.
Weapons as a spellfocus was sorely needed if your table actually cared about this, and now added.
You always had to have a hand free with the old bladesong, which means you could always deal with M & S components anyhow. This brings basically nothing. I fail to see how not effective change is
sorely needed. It's a thematically nice ribbon with only corner case effects within the class itself. It's also nice for things like multiclassing for a shield for when you are not in bladesong, but since that's explicitly going outside the class, rating a class feature as sorely needed to enable it is a stretch for me.
Adding proficiency in all one-handed weapons is really nice vs the old method of only giving 1 proficiency, but isn't huge since you may still take a Fighter dip anyways if you want weapon mastery
I'm a bit more positive on this one, but more for playing with a DM who doesn't customize magic items for us -- having proficiency with more one-handed finesse weapons means a greater chance to find a magical one.
EDIT: Remembering that you can TWF, this becomes better.
Banning light armor is a nerf that I can get behind - Wizards should be in robes not studded leather armor (and is it even a nerf? Mage Armor exists).
It's a nerf, magic armor also exists. And while wizards should be in robes, Bladesingers aren't
just wizards. Bladesingers first appeared in The Complete Book of Elves as a Kit for elven fighter/magic-users in AD&D 2nd - not pure magic-users (whom are now called wizards). They could cast in elven chain and any armor up to studded leather. Since their introduction into the game they have been armored.
Song of Victory got a major nerf but I can get behind that too - I'd much rather have Bladework at Level 3 than the old Song of Victory at 14, and stacking them was obviously not realistic. And the new version of Song of Victory is actually really nice for when you are torn between wanting to do melee damage because it's more fun but knowing that Wizard spells are far more powerful
As you say, a nerf.
So I'm somewhat down on the changes - a minor buff that could also be a trap, a thematic ribbon with little practical effect, and removing armor that has always been part of their legacy, just for an expanded list of one handed martial melee weapons.
EDIT: As mentioned about TWF, the thematic use of a weapon as a spellcasting focus is more than just a ribbon.
I'd still play one though, they left enough of the class untouched it's still great fun.