This is normal behaviour when a 16x strategy is created. The initial test may take up to 2 Minutes. The stopping en route is some mid way re-calibration. If no problems arise burning should continue normally following the (P-)CAV/CLV curve selected as burn speed.
Yes. But that does not mean it'll get used. The 755/760 series work like this:
There is a base strategy per dye and speed in the firmware.
There is a parameterised strategy per recommended media in the firmware.
Non recommended media get parameterised per AS on a base strategy.
If the build in strategy for recommended media is deemed unsuitable, a parameterised strategy is created for them as well.
So if AS is OFF either a built in strategy is used or a base strategy. Using a plain base strategy is IMHO not a good idea. As for the built in strategies it's my experience that they beat AS-created ones in the case of Taiyo Yuden but not in the case of Verbatim.
Because AUTO means the drive always checks the media inserted and then AUTOMATICALLY decides whether a firmware-built-in Strategy or a formerly created AS-Strategy fits this media or whether AS will create an altogether new strategy. This is valid for recommended and non-recommended media.
Media quality varies from batch to batch. Quality may vary so much that the built in strategy is not suitable anymore. This is why AS is a good thing! If the firmware-built-in strategy would not match such a variation AS detects this and creates a new strategy instead of applying the built in one.
For recommended media the built in strategy.
For non-recommended media the base strategy.
You can't. Simply turn it OFF.
No. That just means the drive will ignore that strategy that has been created and stored in the drives nonvolative memory by AS (and eventually create another one).