Mentoring players by spectating a zero-delay Team Builder match

I'd like to suggest a Mentoring system for players to teach those in need;

1. This system will be in Team Builder only initially
2. Mentor must be invited to watch the match
3. Ranked Restricted and banned players may not mentor
4. The Mentor will spectate the match with no delay
5. Fog of War is enabled so Mentor can only see what the student can
6. A VoIP channel could be available between student and Mentor

Seeing as how a Sandbox Mode would be "detrimental", how about the option for players to be coached in a regular match? Some people hit a steep learning curve and can't get past it for years because they don't get any help. Even high tier veterans may want to be coached for a different role, or to finally break into the next Tier.

If you think "They'll just use skilled players to tell them exactly what to do and get IP", well, that would be a big waste of both player's time just getting IP and MMR in Team Builder, but anyway you could have it disable IP and/or MMR gains when being coached.

Anything else that could be added to the system? Anything removed? Submit your bitchings, moans, and complaints in the comments below, and vote in the poll.