About 1440p HDMI issue I tried do manually decode EDID and I found unlisted resolutions there. Whats more in Xorg logs I saw them as well. Anyway when I tried to set res manually (params taken from EDID and Xorg) from xrandr I got error: "Configure crtc 0 failed" and "failed to set mode: Invalid argument" in Xorg logs. This is the case to for all resolutions unlisted in xrandr that I tried (1080p75Hz doesn't work so it's not HDMI bandwidth fault or somerhing). @root-stas I can't locate Xorg.conf, some net sources say it's depreciated and must be created manually. At this point I don't know if adding anything in Xorg.conf can help. I'm not specialist so If you think I should try it tell me.
After fresh install I got Bluetooth working. I have successfully paired my phone with box. Unfortunately XBone controller throws errors but I didn't install drivers for it so that can be the cause. Anyway, to get bluetooth working I have copied more files from git repo provided. by @root-stas. List of files and logs can be obtained from link below. I don't know now which files are needed I have limited time right now. Some analogue files can be found in /lib/firmware directory. For people having trouble with adding bcm4335c0.hcd file make sure name is "BCM4335C0.hcd" (including this sneaky "c").
Logs w/ display issue, bluetooth working and HDMI audio issue
In previous installation I have experienced HDMI audio going down (sink device disappeared), in link above Is a dmesg supposedly from previous installation, but I'm not sure, may be worth checking tho.
When looking at screenshots color issue became more clear to me, Image looks like sheet (unfortunately not white one ). If there is an issue with extracting resolution from EDID maybe there is issue with reading color management info as well.
I have extracted DTB ftom my device boot.img using this tool. It can be obtained here: https://drive.google.com/open?id=12DJoBFrRRP1v2r0ntPCz5LYXP4DRZL1A
And las but not least this "post after next 24h" rule is pain in the heart.