Beginner questions regarding HomeAssistant installation

Hi all,
at the moment I am useing HomeKit with Homebridge for my home automatisation. Furthermore I am using the ConBee2 USB Stick for my Zigbee Devices (Hue and Aquara), Shellys and Zwave (aeotec z stick gen5 via Domoticz). Everything is installed on a Raspberry pi 4 4GB.

Now I want to change everything to HomeAssistant and therefore I want to use HassOS. But I have a few questions:
1.) I want to Install everything on an USB SSD Stick ( SanDisk Extreme PRO 128GB Solid State USB-Flash-Laufwerk USB 3.1). Is that a problem for HassOS? Do I only have to burn the image to the USB Stick instead of the SD-Card?
2.) Which HassOS version should I use? 5.5 or 4.17? And 32 or 64 bit? I have read, that with 64bit the GPIO Pins are not working at the moment.
3.) How much effort is it to update from a HassOS version to a newer one (eg. from 4.17 to a upcoming stable version of v5)? Are all settings from the addons saved?

Thank you in advance!

Best regards,

yes they are

As long as the device is compatible to boot on a Pi4 (some are not a can cause problems) it should work fine.

From the Beta release notes for 0.118.0 (next release version)…

“The last few days two new Home Assistant OS releases have been released. While 4.16 continues to make small improvements in the 4.x release series, the latest pre-release 5.5 comes closer to our goals to declare 5.x release series stable. In particular, this release includes the Linux 5.4 kernel for all Raspberry Pis! We also intend to declare 64-bit the recommended installation method for Raspberry Pi 4”

Based on this info, your could run the latest 64bit Dev build from here.

If you take a snapshot and backup all your config before updating, you shouldn’t have any issues restoring to a new version.