[Monochron]

Just to add a quick bit from mentor perspective, occasionally in dealings with other professionals / administrators there are bits of information that won't (I might say shouldn't) be communicated to students.

Chief among these is usually financial information. If a meeting is going to be held and certain financial topics are going to be discussed, the other party may not want students present. It is usually the FIRST way to include the students in every aspect of the team, and conversely it is often the "professional world" way to bar students from some things. It doesn't sound like all of your issues are because of something like this, but a portion of it (especially the meeting with principles part) could be coming from that.

Alternatively the other parties could have a . . . prejudice against including students in "upper level" talks. Most people in FIRST disagree with this (as do I) but your mentor may be excluding you in order to help the team.

Again, it sounds like you have some other issues that everyone else is answering, I just thought I would give some alternate opinions.