I have zero knowledge on any of this, but just take care with pi-hole + YunoHost, there is an incompatibility with pi-hole version > 3.3.1
Pi-Hole can’t be updated beyond version 3.3.1, because higher versions use an integrated version of dnsmasq. This would require disabling the version of dnsmasq used by YunoHost.
(but there is a pi-hole and a wireguard app too, which is nice)
I tried to read the link you provided and I suggest a way simpler list :
- Install YunoHost on a server somewhere you trust, and on a raspberry-pi
- Install pi.hole in the server
- Install the unbound app in the server
- ??? connect the raspberry to your server via unbound (this is the part I have absolutely no idea about)
- Install Wi-Fi Hotspot on the raspberry-pi
Maybe use the vpn client app on the raspberry, but I do not think it is compatible with wireguard.
Nearly everything is already present, I hope you will manage to build your project 