Noob question re relays

[dreamy dawn]

Hi everyone, in my apartment we have built-in wall on/off switches we DON'T USE. We keep them always in ON position.
Then we have Ikea Tradfri zigbee remotes (5 buttons), that we use to do on-off, as well as dimming, and custom scenes.

We will move to a new apartment, and I would like to nuke this double remote situation. My understanding is that I would need to install relays, but my questions are:

1 - ZigBee seems to be a good energy saving options. What happens if my zigbee network fails (or if they somehow fall out of the network)? Will I still be able to do basic on-off to cut the current to the bulbs?
2 - Would I need to find 5-button wall switches? Do you have recommentations?
3 - Shelly seems to be a highly recommended option (tho it uses Wifi). They have many relay types, which one should I go for?

Thanks

[topaz wagon]

1 - i'm pretty sure that most zigbee smart switches allow you to use the switch to control the directly attached lights even if the zigbee network isn't working.

2 - depends on what exactly you want to control? I don't have any specific recommendations. you could always keep a few tradfri remotes around as scene controllers and remote switches in addition to using simpler wall switches.