People already have the opportunity to kill that achievement and experience by buying silver directly. It's nice you have more soul than the average economist though, I like that, but don't babysit your customers too much now.

The newbie pack if designed right might be a lot more starting experience friendly than them going for the silver instead (is another reason why I recommended to NOT add silver to the pack). Many will probably go for the silver in addition (or only), but at least you'll provide an alternative.
The iron tools was a suggestion, not what I see as a requirement for such a pack (though I know many would appreciate it; if not metal tools maybe something in between those and the beginner tools that where exclusive for this pack? Like I said, be creative

). The inspirational potion and claim thing is the only things I personally see as a must. Anything else is really up to you guys to put together as you see fit, I'm sure you can balance it a lot better than what I could. Either way, obviously a newbie pack is best added before expecting a larger influx of players, it's success rely solely on the rate of new players. If you add it later or don't manage to attract a large enough crowd it won't do so good. So considering it should be done now, not later. That train WILL leave soon.
- The reason for the potion is that there are going to be a lot of enthusiastic beginners that will be running out of inspiration in the beginning until they've built up their rates. The cash shop isn't offering anything to take advantage of this very boring situation. And the few players that sell such potions seems to price them way above a beginners budget.
- The claim is because the community veterans is a group of assholes (me included) that would rob a beginner blind before they had the chance to collect enough silver for a claim. Obviously this isn't good in terms of establishing that essential first impression that would help more people establish roots with the game, which is critical for the long-term success of the game. Ensure smiles in the beginning, let the tears come later.
And in case there where doubts, the inventory-containers was a separate suggestion from the newbie pack. x3 (I really really want this, and is more of a vanity OCD-organizer item than an actual requirement to enjoy the game, so is well suited for the item shop in that regard I think)