I realised where I was going wrong! the command block setting the score to zero was going to fast for the one detecting my score.
I have attached a screenshot of the new layout, so anyone else with the same problem can see what happened.
removing the scoreboard section also works, but when I try to put it back in, the command block forgets it even had output previously.
I just tried a different command in the same command block, and it works perfectly. /testfor @p is fine, so is /testfor @p[name=aether_hawk]
the first two screenshots are from when I initially entered the command, the second two after leaving the GUI and coming back in.
The last is the setup. the not working one is the one in the center. The annoying thing is, the other one works perfectly.
The command in the other one is: /scoreboard players set aether_hawk Sneak 0.
Oh. Thanks. That really had me stumped. that should also help me in future command block contraptions. _
&(O)S
bottom one: /testfor @a[name=<insertname>,score_<insertobjectivename>_min=1]
the middle one: /effect <insertname> <mnemnemneeffect> 1 50 (it is conditional)
and the top one resets my scoreboard score.