🚀 go-pugleaf

>create a really secure Tor server with a raspberry pi?

I assume that you mean a server that offers a hidden service via tor. It is not much different if you use a pi or anything else to host such a service.
The most important part when it comes to security is in my opinion to separate the server from the rest of your network by a firewall (that can be a second pi with an additional ethernet interface). Assume that your server will be broken into and make sure that any successful attacker is trapped behind the firewall. Like that:

internet|<-->|nat|<-->|tor server|<-->|firewall|-->|web server|

>How many "clicks" can i host with this small computer power?

It depends on what kind of service you want to run. From low to high demand on hardware:

-static html pages
-scripted backend (php, python,....)
-voice chat (mumble or similar)
-video chat (like big blue button)

All of this will run on a pi, but the last one will most probably perform badly when too many participants are in. If you only serve static content, I doubt that you will be able to exhaust your resources.
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Posted on Rocksolid Light
dkzerogt6z6ybhcj.onion

>>6b70f3ebe0f95005c9
> Assume that your server will be broken into and make sure that any successful attacker is trapped behind the firewall.

Note that all modern pis have an onboard wifi chip. You can disable it via software, but an attacker can enable it again easily. So even if trapped behind a firewall, the attacker can use the wifi to check for the available networks in the surroundings, which in most situations gives away your position (unless you have no wifi networks close to you...).
Maybe a pi is not the best the best device for this.

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Posted on def2