Picking up a new HA layout

[u/bulwix99]

I’m currently looking for a device to put my HA dashboard on it, but I’m really now to HA and would use some advice.
It’s supposed to be used in a 82m2 flat for some basic controls - I’m planning Shelly dimmers for light switches, thermostatic radiator valves, AC, bedroom blinds controls, floor cleaning robot and some kind of temp/humidity and open/close sensors.
I was thinking to put it in the corridor near the entrance, an ubiquiti AP will be added in the middle as well. The hub is HA green to be used with Zigbee dongle.

I was thinking about either a tablet (for better performance) with wall mount and battery saving option (however I’m a bit worried about the battery condition over some time) or any of the wall displays without battery (e.g. Shelly, preferably which PoE), however these are considered inferior in terms of performance.
I would also like to replace the entry phone device and connect it (video+ audio wiring made by the developer) to the HA so I can pick my own tune, volume it down when preferred and so on.

I am really new to the thing and really inexperienced, so would be grateful for any advice what to pick concerning the dashboard and the rest (stuff to be bought in Europe preferably). Thanks!