It's worth noting that your first link is in relation to the Windows Insider program. The Windows Insider program provides you with pre-release software that does call home with usage details and other information. This is something that you agree to by installing the Windows Insider preview - if you don't like it, you don't have to install it, it's completely your choice.

The EULA for the released version of Windows 10 doesn't include this section and there is no evidence that this information is being collected (which of course could just mean they're better at hiding it).

The second link that you've provided is regarding the Family functionality, this is functionality that has to be enabled in order for it to work and collects application usage statistics and browsing history. In the instance linked in the article, it's perfectly possible that this functionality was enabled in Windows 8 and expanded upon when the upgrade to Windows 10 occurred. On my clean install I don't have this going on so this isn't enabled by default and has to be something that you opt into - again, when you opt into something like this you're given an agreement to agree with stating that additional information will be collected. If the information wasn't collected, functionality like this simply couldn't work.

Windows 10 has a large number of privacy settings - many of these are on by default but they're easy enough to disable by opening up the Settings app and working your way through the Privacy settings. This covers a large variety of options from your unique advertising identifier, which is shared across various applications to allow Microsoft to track your use of the apps and show you targeted ads, to Bing search in the start menu, which will send your search queries to Microsoft Bing. This also includes many settings from older versions of Windows, such as the SmartScreen filter, which sends URLs to Microsoft for validation.

Windows 10 also contains Cortana, with Cortana enabled, you're asking Microsoft to provide you a personal assistant and this will include sending information about your activities (including applications you run, GPS locations, browsing history) back and forth between your machine and Microsoft. This can include things like your handwriting and what your voice sounds like, but these can be disabled individually within Speech, inking & typing within Privacy settings. Cortana isn't unique in this behavior. (How do you think Google Now and Siri work?)

If you sign into Windows 10 with a Microsoft account, authentication is handled via Microsoft as well. This will also provide you with the functionality to synchronize your desktop settings, passwords, web browser settings and more between multiple devices running Windows 10. If these options are enabled then this is additional information that is synchronized to Microsoft's servers. Each of the individual sync settings can be toggled in the Settings app under Accounts > Sync your settings, or you can simply not log in with a Microsoft account and use a local account. If you're using Windows 10 Home edition, you will need to use a Microsoft account in order to enable BitLocker, and your recovery key will be uploaded to Microsoft's servers. This restriction does not apply to Windows 10 Pro or higher.

With the "Sample submission" option for Windows Defender enabled, Windows Defender will send your files off to Microsoft - for example if you had some kind of confidential document with a macro in it that Windows Defender identified as a threat, with the option enabled, this file would be submitted to Microsoft for analysis.

There are reports that even with all of the above functionality disabled some information is being passed back and forth to Microsoft (Arcs Technica), and Microsoft's response on this matter is as follows:

As part of delivering Windows 10 as a service, updates may be delivered to provide ongoing new features to Bing search, such as new visual layouts, styles and search code. No query or search usage data is sent to Microsoft, in accordance with the customer's chosen privacy settings. This also applies to searching offline for items such as apps, files and settings on the device.

It's worth noting that Arcs Technica states this statement from Microsoft is consistent with their findings

Basically, as part of the Windows Feedback and error reporting, diagnostic data is reported back to Microsoft, this can only be disabled in the Enterprise and Server editions of Windows 10 through the use of group policy editor but can only be set to a "basic" mode on Home and Pro editions which "limits the amount of data sent". This can be set in the Settings app under Feedback & Diagnostics.

Microsoft have never hidden the fact that Windows 10 is supposed to be the last major release and that future functionality will be provided as automatic updates. Any such system will require information to be passed to Microsoft to work. Ultimately, there are a lot of components in Windows that will individually and collectively synchronize their status with their online counterparts and this will result in internet traffic.