1) Inventory tracking seems odd to me, unless its primarily to brag to other tea drinkers. I mean I see my tea every day, I know how much I have.
2) I really like the brewing tracking/suggesting. The amount of tea, length of steep, and temperature all make a big difference and it can be hard to remember which caused which flavors.
3) I'm okay with making my tea drinking schedule/habits public, but I'm not sure I really want to push each one out to facebook/twitter.
So in conclusion, my main enthusiasm for the app would be my ability to log detailed brewing trials, and to see what others have come up with. I would worry others might be taking loose or incorrect measurements though, so I'd want some assurance any public notes were somewhat carefully done.