Apple could still single-party screw me, but they're huge, and if they did this in even one documented case they would probably lose $100B in market cap, and Tim Cook has shown he will push back when ordered to do stuff like this.
2) Until recently, the direction they were moving in was good, even if their current position wasn't ideal.
3) It isn't so much that I think they could be malicious as that I don't trust them to have enough internal controls against external compulsion or an employee with prod access getting hacked.
There are some passwords I don't put into 1Password (PGP, etc), and I try to avoid having passwords-only as auth credentials for anything important. So it is more I would have hundreds or thousands of low to medium security site passwords at risk, which in aggregate would be a huge inconvenience. That is more because I don't have huge faith in the local OS security on machines than 1P as a particular risk vector.
I can't put all of my secrets in a file, encrypt it with software a site provides, let that site push updates to me for that software, and then give that site the resultant encrypted file to sync. It's not quite as bad as a pure web based password manager with JS crypto, and better still than a web based SSL transport-sec-only password manager, but still unacceptable.