safelife, as regards to this being a pro-only forum, I think you'll find that that ship has not only sailed, but has long since disappeared beyond the horizon never to be seen again.
AF330, the links you posted describe the functions of those switches pretty well, but I'll give you a little more info: a manual start can be performed regardless of what the bleed source is. The circumstances under which a manual start may be called for vary by airline, but typically a manual start is recommended (though not required):
After aborting a start because of:
•Engine Stall
•Engine EGT Overlimit
•LO START AIR PRESS
•No N1 Rotation
•Hung Start
When expecting a start abort because of:
•Degrading bleed performance, due to hot conditions, or at a high-altitude airport.
•An engine with a reduced EGT margin, due to hot conditions, or at a high-altitude airport.
•Marginal performance of the external pneumatic power.
•Tailwind greater than 10 knots.
Hope this helps.