I am thinking to buy some Dell WYSE Thin Client DX0D, AMD G-T48E 1.40GHz, 4GB DDR3, 16GB Flash
or HP T610 Flexible Thin Client, AMD G-T56N 1.60GHz, 4GB DDR3, 16GB Flash in order host them at friends/family and to install Snowflake Proxy where i don’t have a fixed IP address and obfs4 where the IP address is fixed.
What else can i do on this machines to help the Tor project and to have a free and open Internet. Hence some of them can be upgraded to 8GB of RAM can i make them middle/guard nodes?
Those family are aware about risks hosting stuff like that ? 
what is the risk of running snowflake, bridge or middle-relay except traffic usage?
None, afaik. Except maybe if you open up a firewall to get more traffic. Snowflake is not an exit node.
The developers have frequently pointed out that there is no danger to those who host or use snowflake.
As always, I welcome corrections.
As far as i know the only legal concerns may occur only during exit nodes. And that is the only risk that can happen but with Snowflake - obfs4 there is no risk, and as far i know also for a middle/guard there is nothing that can happen because the traffic is encrypted and ip address is not exposed (opposite to exit node)
As @atari and @Quartermarsh said except bandwidth there is nothing on the table.
I opened this thread to find out if the thin client can be used as guard/middle node and if there is something else i can do with that kind of hardware in order help the network because ii already know the hardware is good enough for Snowflake and obfs4.
@red0bear i don’t need misleading information and fake infos 
@SirNeo There are new protocols (like conjure: The Tor Project / Anti-censorship / Pluggable Transports / conjure · GitLab) in the works which we’ll be able to add to our anti-censorship toolkit soon. 
if you have a static IP, you should run a bridge imho - but hardware would be sufficient for a relay with around 2-3 MBytes/s I guess