Great questions. I’d be interested to see the manifest file also. Hopefully, somebody from MDG can provide a link?
From my preliminary tests, yes and yes. To the point that there are some mix-and-matching rules which I don’t fully understand. One thing I know is that I’ve had to publish all the packages in the release with the previous Meteor build.
That is, a release can’t be published if it has packages with api.versionsFrom() that specify a later Meteor build. We had some packages published with Meteor 1.2 that had the ecmascript package automatically installed, and that broke our clinical:METEOR@1.1.3-rc6 release. So we had to go back to those packages and publish them with basic Meteor 1.1.3.