WHY U USE BLUE TEXT!?!?!?!
You can also get the pro version of Iseeyou app, which allows you to adjust the times i.e. how often it checks to see that you are still looking at the mobile. I was a bit hesitant at first trying it out due to all the poor reviews but it works great on my 1S, from what I can gather it also works very well on the GS 2 so it should on the GS 3 as well.
As for the other motion stuff, I have no idea

I imagine that there are a few apps out there that cover some of the stuff, but I am just not aware of them
I think this is a better alternative to smart stay personally:
https://play.google.com/store/apps/details?id=com.keyes.screebl.full&hl=en
Google now has already been ported to devices

Only the voice feature isn't working, I am sure that will be solved soon enough though.
http://forum.xda-developers.com/showthread.php?t=1747224
I can't see there being any stock JB ROMs that will have Samsung features any time soon.
I have had a quick go with the GS 3, not used all the features though, but personally for me they aren't useful and no better IMO than the other alternatives, I like the smart stay feature, however, it is pointless for me as the main time that I would need it, would be at night time (lying in pitch black in bed reading web sites etc.) but due to the nature of the camera, it won't work in that condition, and I am happy with manually locking the device myself or tapping the screen every now and then within 30 secs for now

Also quite like some of the gesture based stuff.
The turn over to mute feature, I have on my 1S (stock sense ROM), but never use it, if I don't want to speak to someone or can't I just reject them

I actually think you can change it on sense so when the mobile is flipped over the incoming call is hung up instead and a message saying whatever you want e.g. "sorry can't talk in a meeting" will be sent automatically to the caller that you just rejected (need to check this again to be sure though)
Personally don't like notification toggles in the notification area, I just have switchpro widget on the homescreen.
EDIT:
Just flash a touchwiz JB ROM that has the JB theme and freeze all the apps you don't need using titanium.