There is no real difference between using the Bigby interface or right-clicking the Faded Death Cube from your NX tab, it's just flashier. Dimensional Orbs has been used as the interface to open the Glorious (Valkyrie gacha) and Steel (Iset/Keaghan gacha) Cubes, which are purchased from the supply depot during their specific sales. There are currently no boxes to purchase that use the Dimensional Orb system.
For those that don't know, the coupons basically work like this:
On use, the coupon rolls between 1 and 5 stars. [My personal estimations are 1 and 2* rolls are ~65%, 3* rolls are ~30-35%, 4* is ~1%, and 5* is under 0.5%]. For instance, the coupon rolls a 2* in this case.
The next step is checking if the item is under the coupon level. If the item matches or exceeds the quality roll, nothing happens. Otherwise, the quality is changed to the roll of the coupon.
In general, you'll want to follow the main storyline (and if you care about titles, make sure you do the sidequests that are hidden by default). Spending AP is fine for two reasons - you can get unlimited amounts of it by playing so all skills can be maxed out, and a skill reset is given in the growth reward for reaching level 90 in case you feel you made a mistake in distributing it.
1. Will uncollected mail be negatively impacted in any way? For instance, I have story items on some of my characters that were delivered through mail, so I'm just making sure there's no random mail wipes I should be wary of. I also have the Rockstar items that I left in the mail, would hate to see them randomly poof.
2. Will guild member caps be lifted/removed? 200 members is a bit small for alts and incoming populations.
3. Is it possible for you to do some kind of multiplier on the gold that AUS members have? Their economy is drastically different, so something along the lines of multiplying their gold by something, for example 5x, during the merger might be beneficial.