I was under the impression that only the relevant permissions to the components included in the change set were sent over, but in uploading change sets and validating them, I'm getting validation errors for completely unrelated components.
Specifically, I'm pushing over fields and record types on a custom object from our dev org to our preproduction org (these fields were just created), and first I was getting errors for an unrelated missing custom tab. I corrected that, and now I'm getting errors for a missing page layout on AccountContactRelation (another dev is working on that and it is not ready for deployment). My components in no way interact with this object or its page layouts. These errors refer to stuff that does not exist in the target org, which indicates that something was brought over in the change set.
Does pushing over the profiles send EVERYTHING for the profiles over? If that's the case, why are we forced to specify a component in the change set then?