Acer T04 (z630s) multi user service

My new Acer friends,
there is a mother of 3 wonderful young girls.
My husband lend me his Acer account to make this post.

I bought a smartphone Acer liquid Z630S (T04) attracted from the cheap price and hight performance.
Effectively the smartphone is very good... but I could not imagine that the multi user service is disabled in all the Acer smartphones (the customer service Acer told me like this).

I work as model, I have my private pictures and videos in my smartphone; I can not allow my daughters to see my gallery, but also I can not deny them to play with the games of my smartphone.
So, tired to change SD card more times everyday, I was forced to install the root privileges on the smartphone and to activate manually the multi user service.
That mean that I lost the warranty on a new device.
In more, the firmare updates are not available for rooted devices and Acer does not release in his official website the firmware updates (like almost all the others productors).
There is no flashable zip, no firmware, no tool to flash. There is only the source kernel file.
So, it is assumed that a regular customer of the Acer would have to be able to buil from himself the kernel source code with Linux.
The Acer customer service does not give any help about this.

I never would advise someone to buy an Acer device.

Personally, I made in present the Acer T04 to my husband; now I have a Sony, full working in all his aspects and services.
Better to pay something more, but to get a device full working with all service actived.
I bought a smartphone even to protect my privacy through the multi user service.
I do not see the sense and the logic to cut off a so usefull and essential service.
It is a pity that a so powerful device is mutilated of a so important service.
The smartphone is like a personal computer: the multi user must be working.

I hope that this comment will help the Acer to improve his services.
Greetings.