As suggested by Mark, I am creating a separate thread for each problem I had reported earlier.

Initial Question - As soon as free RAM reduces to 300 MB or lesser, background apps start getting killed. I get the popup message stating so&so app force closed even though I am not using them. With 250 Mb or lesser even foreground app gets killed. This is absurd on a 1GB RAM. Are you looking at reducing the min free RAM setting to 100 MB or lesser?

Apps mostly used - Facebook, Google+, Hangout, Twitter, Touchdown for Exchange, Angry birds epic, Fruit Archery, Chrome, Gallary, Whatsapp, Gmail, Tapatalk etc

Most of these app get killed along with these apps running in the memory - Viber, Zedge, Google play service, settings, google keyboard etc.

I figured out Once I switched back to Dalvik, these app killings no more give a message most of the time. But they get killed. You can test by opening most of the above apps, browsing them to a certain point and click on the home button. After a few mins open apps like Facebook, G+, Twitter and you will see they are loading again and they take you to the beginning news feed instead of opening at the point where you had left. Open Chrome and it will start loading the last page you had visited as it was silently killed.

Kitkat build of my phone ends with .14.