Boofhead
Some answers to you questions from a LAME's point of view.
Battery is ready for the next start when the load meter drops below 40% and yes I would recomend cross generator starts but only switch on the generator once the starting engine has reached 12%Ng to reduced intial load on the running generator.
Auto feather test has been explained but you must ensure the condition levers are at low idle or the torque won't drop off sufficently to trigger the autofeather. Under the system we operate with auto feather is not a no go item. The KA does not come standard with autofeather so I don't see why it could be mandatory but that depends on the reg's you are operating under.
Never try to modulate the start with the condition lever. It is all preset at the F.C.U. Going to high idle during start will have no effect below idle speed as the F.C.U. is on the min flow stop. Going to cutoff and back to idle is a definet no no. depending on ones interpretation of the maint manual this could be taken as an inadvertant relight which requires the engine be removed and sent to an overhaul facilty.
Feathering after shutdown is easier on the engine but you must feather before shutdown if you want an accurate measurement of oil quantity as the oil from the prop takes time to be scavanged back to the tank.
Cheers