Umm, you have understood a good portion I may be misinterpreting what you are saying, but you'r mind & the mind of the parallel you are swapped. Present you will now be face to face with the same scp except it is now able to perfectly outmatch you. When you die it then renters you, seeing as you are stuck in the room with the scp no subjects have been able to escape attack as of far. If you survive attack you will be returned & the scp will simply 'give up'. It is unknown why it does not pursue. As far as your listed questions go:
1) The scp doesn't appear to wan't to put itself in danger of a fight & why fight at all when it can send you across to the 'optimised' version where it is much more likely to succeed in such attack.
2) Through the few who have survived any attacks & also a sudden change of emotions has been noticed backing up people who survived's tales. Before the foundation found any survivors they did believe this scp's anomalous properties only went as far as suddenly killing those it knew the presence of.
3) For the alternate idea, I thought it would be interesting if this scp could be the cause of all scp - related deaths. It would bring a lot of depth to this scp's story. As far as why it would do this, it is unknown by the foundation, however if you want some reasonable concepts why mabie it can only transfer to those who are close to another scp, or it couldn't care less if you knew.
As far as your containment concepts go, this is a great idea for containment, it does contain some of my pre-conceptual ideas of how it could be contained (soundproof walls, I was originally thinking no windows at all but cameras, however one way glass could work better). Your concept of containment does go into higher detail than my pre-conceptual thoughts so this has been very helpful. Thanks
