Yes, but in general terms only.

Both, in order to minimize conflicts.

Sponsors usually take an active role in selection of the PM, but take a passive role in functional staffing so as not to usurp the authority of their line managers.

There is no really effective to do this other than by closing out some of the functional charge numbers.

Yes, if mandated by senior management.

The PM can request any skill level desired, but the final decision almost always rests with the line manager.

Both.