I'm trying to piece together how to root my Xperia Z1 that is currently on build 14.2.A.1.136 and whilst there are many guides that all link to each other, there is a lot of assumed knowledge.
I've been rooting and flashing stuff since the first XDA so it's nothing I'm new to but there's gaps in my knowledge as far as Sony devices go and it makes me a little nervous to try this without filling the gaps.
I've seen Shem's video (here http://www.youtube.com/watch?v=1aq9YTlfCgc) about downgrading to .534 using NUTs files but there's a lot of RED warning spread around various posts so, if you'll bear with me, I just have a couple of questions...
1) There's a warning on one post about backing up the TA partition before unlocking as the DRM keys will be lost. I understand what DRM keys are but is there anything else on here that's needed? Will I need to do this TA backup before I downgrade to 534 or upgrade to 290? or root?
2) I've downloaded flashtool for the Mac and the 534 FTF (FTF is just a Sony firmware file prepared for flashtool, yes?) - is this FTF file model agnostic? I've got the C6903 which is the LTE version of the Z1...
3) The stripped FTF files that are linked to under the video...are these the files you use to upgrade from 290 to 136 whilst maintaining root?
4) Am i right in thinking that I don't need to mess about unlocking my boot loader or flashing a custom bootloader if I'm not interested (at this stage anyway) about flashing a custom ROM but just keep root on stock...?
I suppose what I'm getting at is which part of all these processes is the dangerous bit where you need to take care? I hate losing anything permanently and whilst there might not be anything I need my DRM keys for (I got some free films but y'know, alternate sources are available) I don't want to lose the Bravia engine or any other functionality of my phone because, aside from anything else, it will affect the resale value and I look after all my phones as they fund my next one when I sell them on ebay.