for deleting all the channels I guess you can only use the brute forcing method like the one I used for some of the other tests available in my PoC.
if you can't recompile the PoC it's enough that you modify the executable with a hex editor, from:
clientkick clid=%d reasonid=5
channeldelete cid=%d force=1
remember aspace or a NULL byte to cover the last byte not covered by the new string ('5').
then you can test it with bug 8:
teamspeakrack 8 SERVER PORT
so this same method should be used for any other ID related operation because, as far as I know, there is no way to see the IDs through this vulnerability.
while for the question about adding someone as admin I guess you must refer to the ts3 ServerQuery Manual because I'm not an expert of ts3 administration which looks a complex thing (tokens, ids, blah)