Lots of questions here reference Ethereum Alarm Clock as a way to schedule events. It seems to my eye to no longer be operative. Is that the case, or am I mistaken? If it's isn't operative, is there another service that offers similar scheduling functionality?
Yes, Ethereum Alarm Clock is alive and well. It's on mainnet. In the first few months it transferred more than 1000 ETH safely. It has also been audited by BokkyPooBah.
There's also new page: https://www.ethereum-alarm-clock.com/.
Ethereum Alarm Clock is also integrated as
Send Later button in MyCrypto. Here's tutorial how it works.
Also support for transferring ERC721 (aka Cryptocollectibles aka NFT) has been added to EAC Chronos DAPP, so you can transfer CryptoKitties and other collectibles.
Based on their gitter, no. The service is currently inactive. https://gitter.im/pipermerriam/ethereum-alarm-clock. Best to get in touch with https://github.com/pipermerriam/ to check on a reboot schedule.
I think they're reviving it. The new gitter is https://gitter.im/ethereum-alarm-clock/ethereum-alarm-clock.