[Tablet] How to dual boot Lollipop 5.1.1. and Ubuntu on Tablet?

Hi,
I've been an happy Ubuntu user with my laptop for over ten years.

Now, I need a Tablet. The one with Ubuntu touch was too expensive for my budget, so that I bought a second hand Samsung Galaxy Tab A LTE 9.7.
It has Android (Lollipop 5.1.1.) and 2 GB RAM. Here all details: http://www.samsung.com/it/consumer/m...SM-T555NZWAITV

Could I manage to install a Dual boot with Ubuntu (be it Ubuntu desktop or touch)?
If not, could I easily replace Android with Ubuntu Touch?

I'm not a very experienced user, but in the past I had managed to install a dual boot with Windows and Ubuntu.

On the web, I have found some information but no exhaustive responses and users experiences.

DUAL BOOT
http://askubuntu.com/questions/66828...axy-tab-a-t350
http://askubuntu.com/questions/35916...xy-tab-2-p3113
http://www.phonearena.com/news/Ubunt...50662/Idea
http://www.xda-developers.com/dual-b...rs-holy-grail/

I have found these guidelines, but it says it's only a "tech preview for developers", so I guess not for me.
https://wiki.ubuntu.com/Touch/DualBootInstallation

UBUNTU TOUCH INSTEAD OF ANDROID
My device doesn't seam to appear on the list of supported devices (https://developer.ubuntu.com/en/star...vices/devices/)
http://www.pcadvisor.co.uk/how-to/li...image-3531970/
https://developer.ubuntu.com/en/star...u-for-devices/

From what I understand, Dual Boot is difficult to install, while replacing Android with Ubuntu Touch shall be feasible. Any experiences?

About Ubuntu touch, I'm not sure about its limitations. For instance, can you easily install common apps?

Thank you for your help

Best,
f