What are ideal temps? What is the danger range? Is there any link between WiFi being used in Pi vs Ethernet? Also is Pi generally hot or depends on what softwares are installed and what activity it is doing? Like say it may get hot when actively downloading torrent or streaming via jellyfin etc but won't get hot when just lying idle with say only PiHole running?
Generally the Pi 4 starts throttling if it goes over 80C. Generally mine runs at 45-50C in an ambient temp of 30C. Keep in mind though I use the passive Aluminium full contact case which does a pretty good job and my CPU usage never breaches 50% even with 30-40 torrents being downloaded at a cumlative speed of 10 MB/s over nordvpn.
Pihole resource usage is minimal. Check the Status tab on an anemic Pi Zero W which is glacially slow compared to the Pi 4.
I recently learned about Docker. On YouTube, I see videos where they installed the Torrent client, sonarr etc through Docker.
Is there any benefit of using Docker to install some apps on raspberry pi (dietpi) instead of natively installing (through dietpi list of softwares)?
Can apps installed using docker still see mounted HDD fine?
Another question is, in dietpi documentation for torrent clients, I see it says I should have one of the file servers installed. What is the reason for that?
First you gotta walk mate before you start running.
Containers work a little like VMs, but in a far more specific and granular way.
They isolate a single application and its dependencies—all of the external software libraries the app requires to run—both from the underlying operating system and from other containers.
All of the containerized apps share a single, common operating system (either Linux or Windows), but they are compartmentalized from one another and from the system at large.
Please note that you need to be a bit more proficient with *NIX if you are gonna work with Docker rightaway.
I use the samba server for connectivity through Solid File Explorer on my phone. NFS is for access through Windows PCs. vsftpd is for SFTP.
And before you start tweaking around with custom installations always take a backup so that you can roll back easily. I have burned my fingers quite a bit because I didn't get habituated with it in the beginning.