Orange Rono (Zte Blade Vec 4G) totally messed up - RO memory - Help please

How did I end up here?

1. Installed CM 12.1 Beta 4 from our friendly user forumber via TWRP
2. As GPS and camera didn't work, tried to get back to stock
3. Tried to flash 5 different roms (2 custom & 3 officials) but "error executing updater binary" just wouldn't let me
4. I don't know how but I finally managed to flash Yoigo stock one (Actualizacion_Blade_Vec_4G_Yoigo_V1.0.0B04.zip)
5. TWRP & Root went off. The entire internal memory is now on read-only memory.

Can't download a single file from the phone but somehow I can install apps via Play Store (pretty much the only thing I can do).
The only progress I made so far is to get root back again via Windows Kingroot.
Adb is working properly but mount command tells me operation not permitted
What should I do now? Replace Kingroot with Supersu? Change ro.secure parameter modding boot.img?
And most important: giving the circumstances, how could I do what you suggest me?
I should point out that I know nothing about programming and having got so far surprised me.

Thank you everybody in advance.

P.D. I don't know if the code I'll post will tell you something, but this is what cat /proc/mounts tells me:

Code:

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shell@msm8226:/ $ cat /proc/mounts
cat /proc/mounts
rootfs / rootfs rw,relatime 0 0
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,size=419008k,nr_inodes=104752,mode=
755 0 0
devpts /dev/pts devpts rw,seclabel,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,seclabel,relatime 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
none /sys/fs/cgroup tmpfs rw,seclabel,relatime,size=419008k,nr_inodes=104752,mod
e=750,gid=1000 0 0
tmpfs /mnt/asec tmpfs rw,seclabel,relatime,size=419008k,nr_inodes=104752,mode=75
5,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,seclabel,relatime,size=419008k,nr_inodes=104752,mode=755
,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/platform/msm_sdcc.1/by-name/system /system ext4 rw,seclabel,relatime,
data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/persist /persist ext4 rw,seclabel,nosuid,
nodev,relatime,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/userdata /data ext4 rw,seclabel,nosuid,no
dev,relatime,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/cache /cache ext4 rw,seclabel,nosuid,node
v,relatime,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/modem /firmware vfat ro,relatime,uid=1000
,gid=1000,fmask=0337,dmask=0227,codepage=cp437,iocharset=iso8859-1,shortname=low
er,errors=remount-ro 0 0

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