Hi Olympia,
As Andreas Told, I accpet with them and also for question
2. What is the best practice for GTS setting: System Response in Feeder System if SAP GTS Fails?
In the control settings for System Reaction : Output Dailog in SAP GTS --- If we check this, system will give a pop-up window Examples: that Some Partner is missing or Document is blocked or License is missing etc.,
So this thing will happen when you maintain the Value (A) in the above said field. If you maintain blank in this field even if GTS System fails, the system behaviour will be like it will allow to create the subsequent documents furhter.