Taunt
Should be moved in to Allowed, as this move provides great potential for any lead sets and provides great support for allowing CaP 8 to come out and stop opponent set-up strategies, while coupled with it's great physical bulk allows it to be a great competitive and non-broken move.
Both Light Screen and Reflect
Should be moved into allowed to create a more viable support role. A good example of this role is seen in Starmie who has good typing together with great Special Attack and Speed stats allowing it to be a great special sweeper. However, when given Light Screen/Reflect opens up the potential for a great supporting role, which can be very important in team building and the over-all usefulness of a poke.
I don't believe Light Screen is too much for this CaP especially when considering any other poke can set-up a Light Screen for it, it's not really as broken or impenetrable as everyone seems to claim it is.
As for healing I believe the options of either Synthesis, Moonlight, and Morning Sun should be placed in allowed (Pulling for the latter two based on flavor, as they all have the same effect). This allows CaP8 the option of reliable healing that isn't too good for this CaP, like Slack-Off or Recover which should be moved to unallowed. As they can be hindered through often used weather such as Sandstorm, although can be supported through the use of other weather users for the increased 2/3 health regeneration. Which I believe opens more team building options for this CaP as well as keeping it balanced.
As for stat upping moves I believe Dragon Dance, Cosmic Power, and Calm Mind should be all placed under allowed. Dragon Dance allows the use of a more physical attack set of this CaP as well as providing Speed that this CaP may require. Cosmic Power can remain very useful when provided a recovery move (such as the already suggested Synthesis, Monnlight, and Morning Sun) that will this CaP with it's great tanking potential. I believe for the more offensive sets Calm Mind is a great way to go as it adds to CaP 8's great Special attack stat while helping CaP 8 with it's poor Special Defensive stat, which helps it as a special sweeper. Also, Calm Mind is balanced IMO in that it doesn't raise Speed like Dragon Dance and many counters may be using it's average speed as a tool to counter it. I also wanted to adress people claiming any of these stat upping moves as "broken" or anything along those lines. Frankly, Salamence and Gyarados are great examples of using stat up moves to help them and they surely aren't broken and CaP 8 can be stopped in the exact same way as those two. Especially as things like Hippowdon can come in and force a switch or Roar you away. And again, if you're not ready for a stat upping CaP 8 you would already be failing against a large chunk of the current metagame (again through through the likes of DD Mence, Gyarados, or Calm Mind Latias or Suicune for example).