Yes, and pretty easily if you buy into all the new features that no one else will ever have all of. If you stay clean with simple storage, compute, DB, email, then you should be okay.

Ideally you'd have some kind of plan though from the start, for which other cloud provider you would use and how the services would map, in case using AWS becomes untenable.

Cloud product life cycles should definitely be more interesting. Azure for example already has a "classic" model and the new ARM model. Either way, avoid tightly coupling code with some external vendors service.