The Raspberry Pi 5 might be good enough for your needs. The 8GB costs a bit less than 100€ without any accessories at the danish reseller, so it fits in your budget. I don’t know if it’s good enough for all your services.

Should work, tho I doubt it’s much more performant than a pi, so your ideas might be too heavy for it.

You can, just go to the sidebar and press Pair new device.

Wait how do PDFs relate to this?