Shouldnt Firefox or a Fork of Firefox like Waterfox or ZenBrowser be fine?

Okay that sounds pretty impressive

You should be able to deactivate shutdown or sleep mode on lid closure with some commands.

I'd say it depends on your needs and budget Framework has a higher build Quality and a bit loser prices but if this isn't a Problem for you, go for it. Great repairability and replacebility is awesome!

Thank you for providing a better Source and editing the post!

By adding launchers you can customize the Android "desktop" way more in depth and it enables you to add for example custom app icons