1. do i need to be on stock rom or any stock based rom before flasing this through recovery....
I was on liquismooth, full wiped, flashsd paulicat rom, later flashed sling rom WITHOUT FORMATTING SYSTEM. And everything works.
2.will this flashing erases internal storage also.....???
No, it didnt for me atleast
3.will this erase recovery......????
No, and it didnt lock bootloader either(for me)
4.i once tried vdt v12 rom gave me secure booting error.... is there any chance of getting that error again.. if i flash this one...
I am not sure about that, because i havent tried vdt rom. I suggest you flash paulicat stock first, then sling v2, then the update to v2.1. Thats what i did
Or follow the great guides here written by smarter members than me
Anyhoo, i cant guarantee it works for you, but im pretty sure it works as i have e975 too and dont think there is that much difference
Sent from my overheated phone while browsing cat pictures