Are they really worth a mastery point?

Only Biscuiteer, explorer, and wealth are only good at the start, but i'm very sure they're worth it.

With Pickpocket, it seems like I get hit back every time I try to pickpocket them.

I'm currently trying them out, but what are your guys opinions.

I wish pickpocket actually was stealing gold from the opponent :/

And as far as biscuiteer, I don't know, I think if it is just 1 biscuit, then it totally sucks, but if it regens it might be better. But still, that's taking a valuable item slot for a REALLY crappy heal.

It gives you a 1 times use biscuit that restores 80 health and 50 mana over 10 seconds. I usually do put points into it so that I get the starting ward. Then I can spend money on stuff I need in the beginning instead of wards. (later on taking sight stone to eliminate gold I spend on wards all together

I use all of these on my supports, and generally start Faerie charm, Rejuv bead, and 2 wards. This gives me 3 wards and good sustain for mana and HP until my first back. Pickpocket doesn't seem to be very useful... it seems like it only goes off once, even if you make multiple autoattacks.

it has a five second cooldown i think

It's a 5 second CD, so it's encouraging you to hit and run constantly. It's not a bad thing to learn btw.

Pickpocket is nice if you can manage it without getting into trouble. The flask may help with this, though it seems awfully weak. I'm not a fan of the biscuit or the crappy pseudo ward, though. It doesn't buy me enough time to get my philo+sightstone.

Perhaps the pseudo ward would be better served by placing it at your team's red/blue buff (whatever camp your team is NOT jungling). This will give your team advance warning on an invade while they jungle the other buff. Even if the enemy steals the warded buff, it will help your jungler plan a better jungling route.

I think the ward is best used during invades. Drop it in your own jungle as your moving into theirs as a key point and it may let you know what their intentions are.

The ward is not a full ward, its a 1 minute ward. Honestly, I've been using it and its ok but I can't say its the best choice with any degree of certainty. You shouldn't be "trying to pickpocket" you should harass as usual, getting in a free hit whenever possible, and it will pay off. It's not worth it if the trade costs you a potion.