okay lets clear those things
i guess this is the official PWI v621 client, but i guess you can use every version till base descent up to imperial fury (already tested), you need to replace elementclient.exe, elementskill.dll (already in forum) and data files (already in forum)
this does not matter. if you dont know what are you doin, just keep element folder and delete the rest, means config/launcher/patcher, you will never use them, and set proper server config follow the exciting formula in element/userdata/server/serverlist.txt
343's release is 136 and maybe 144 (was a thread about he will make one, idk its done or not), this thread is about v145. just download your favorite virtual stuff (vmware or virtualbox[<- recommended for beginner]), or other computer and set up urself via following tutorial
ofc its work. sELedit support all version from v136 -> v145 v70
you must replace the elements.data in serverside too.