Oh yea, regarding the wifi sense... Most people I've talked to who have actually installed win10 and done specific exploration into it, have found wifi sense to be DISABLED by default. To make it work, you have to turn on about 3 or 4 options, in order to use your computer to share your wifi credentials (a hash, not the actual password) with your contacts.
For anyone you give your password to in order to connect to your wifi to share your credentials with or without your approval, they have to have the same few options turned on (off by default), and then they have to check a box when they enter in the login passkey.
The main kludge for wifi sense is that for you to opt your wifi out completely, you have to add something like "_noshare" to your SSID. That's a total kludge, but doing that will supposedly automatically filter out sharing attempts (with a delay of up to a day or two due to opt-out list propagation across MS servers).
Regarding sharing updates P2P, that's irritatingly enabled by default but you have 2 alternative options. You can disable P2P sharing of updates entirely, or you can enable it only within your own subnet/LAN/domain. That has the potential to save a bunch of bandwidth if you have a bunch of computers on your LAN, by disabling global sharing but leaving P2P update sharing enabled for your LAN. Yea I think a lot of people would have preferred that to be disabled by default and users given the option to "enable faster updates by sharing updates with computers near you" or some equally benign wording, but I think MS really wanted to speed the adoption of win10 in the first few weeks and the P2P defaulting to ON was probably part of the plan, I'm guessing.
