So most of your points are actually in favor of beta 1.3. (3, 4, 5)
What I actually see is you overdoing it big time, trying to take loads of shots at once. You know that the phone also needs time processing them, which eventually WILL pile up as can be seen in your results!?!
Of course the viewfinder starts lagging if you force the app to process multiple shots in the background up to the point were it won't let you even take shots anymore.
HDR+ relies on multiple frames being processed, you are basically filling up its "cache" with the way you use it. Especially in low light this might happen even quicker.
That said, I do not have most of your "issues". I get a slight lag sometimes in the viewfinder, but nothing which would break the app for me.
I know it is always good to get a second person confirming certain issues, but I won't be sitting here taking multiple shots just to "break" the app on purpose.
I did so once for the selfie camera before I posted the info, but that was just to stress-test it. No crashes whatsoever.
From what I see in your post, the app is actually REALLY stable as it appears it did not even force close once for you.
I stand to my opinion that beta 1.3 is the most stable version so far. Takes EVERY shot and doesn't crash on selfies anymore (fingers crossed).
The only "issue" is the blue/green tint.
Thanks
@Arnova8G2!
edit: after re-reading my post, I actually sound pretty rude. I really mean no offense towards you.
Probably phrased it that way because I'm hungry. Sorry^^