I have a (blog) post on that - What's on my Phone in 2020.

For contact lists, I run a CalDAV server at home (Davical), but I'm not sure how to easily blacklist contacts from one source.

Depending on the make of your phone, it hopefully has an USB port. Nowadays, this USB port can often work as USB master too, so you can simply plug an USB hub into it and then hang a keyboard and mouse from it.

If the phone also has USB-C, it maybe even has HDMI-over-Thunderbolt-over-USB-C, and you maybe can use an USB-C -to-HDMI adapter to connect it to an HDMI display.