Starfall Is absolutely worth speccing into. Its a dps increase of a total of ~125 (depends on gear).
Typhoon Is NOT worth speccing for PvP. Unless you priority is on having a huge DPS on trash.. You say that it hits for an average of 3.3k. This can be made to ~3.3k DPS, because that there will be ~1 sec of GC. Most of moonkins is above 4.5k dps, and therefore Typhoon is not worth using. Simple math
Even if you have to move at a bossfight, you very often have to refresh your IS, MF and rarely FF. And Furthermore. Typhoon should ONLY be used when you have clearcasting. This will take your consentration away from the bossfight, because you have to look at your buffs all the time (Even if you have a combat text, and "Clear asting" pops up in the middle of your screen it will take a bit away of your concentration). And if you are casting, and notice the Clearcasting in the middle of your SF cast, you will HAVE to stop casting, for keeping clearcasting for typhoon, and therefore loose alot DPS that way (If we say, that your SF have an average of 7.5-8k, you will loose ~4k damage).
So.. All in all. Its NOT worth speccing.. Only for PvP, trash, and having fun, pushing people over edges, so they die from fall dmg ;D