Personal team note

This team you've planned is very susceptible to burst damage, including Alchemist due to his ultimate change.
You have to get a bkb on alchemist now as he needs some space for his regen to work, I agree that radiance is not needed on him.
And your aim is to give space for Alchemist to carry for late game. There are many carry's that can out carry alchemist so wasting your window of opportunity when he will be at his strongest.
And for the record, Shadow Demon cannot get rid of warlocks golems anymore, but a diffusal blade still can.

Radiance isn't really needed on an Alchemist. He already has Acid Spray, which is much better for farming since it lowers Armour and deals COMPOSITE damage (meaning it even works against Mud Golems and Ancients). Not to mention an Alchemist that's been given enough space to farm an early Hand of Midas should be able outfarm anything they throw at you. Getting Radiance will just force him to farm for longer to get his Core Items, while the rest of his Team try to protect him.

Also, Abysall Blade is useful for locking-down Carries after they've bought a Black King Bar, not for it's amazing 6 points of Strength ;D.

I would consider getting an early Mekansm on OD rather than Warlock, especially if you want Alchemist to be farming for quite a while. OD can easily rush a Mekansm in 7-10 minutes, whereas a Support Warlock will be hard pressed to manage it in 20. Not to mention, an OD with Mek 10 minutes in can Tower Dive Tier 1 Towers and barely take any Damage, allowing him to be more Aggressive, forcing attention away from your Farming Alchemist. Force Staff will only give him 3HP/s Regen, so boosting that to 8HP/s will allow him to stay in lane longer.

I would also consider a Scythe of Vyse more important than a Rod of Atos, it only provides 60 less HP, but the increased Armour will more than make up for that. Hex is generally much better than Cripple too, it does more for only 0.5 seconds less duration. The only downside is Sheepstick costs an extra 2575 Gold.

Rather than trying to farm a Sheepstick on a Support, you might want to consider getting a Blink Dagger for Rubick as he is the only Hero on your Team that can Initiate with an AoE Disable from Spell Steal (unless an Unstable Concoction hits them while they huddled up).

Timbersaw should never be in a Dual lane, he needs Levels to be effective and having a Support will only slow him down, rotating them in to help him Gank might be necessary though.

Personally, I would change Warlock for a Support with a strong AoE Disable, like Nyx Assassin's Impale, Jakiro's Ice Path, perhaps even... Black Hole? 8D