I haven't seen any ads except in Solitaire.
Wi-Fi Sense is enabled by default, but you still have to explicitly tell Windows to activate it for each separate network you join. It won't share your password unless you tell it to in the wi-fi setup. The password is not transmitted to your friends even if you do elect to share via Wi-Fi Sense, only an encrypted hash that enables internet access but no computer discovery on the network. I'm not worried about Microsoft having my wi-fi password. Apple does something very similar and I haven't heard any complaints. It stores your wi-fi passwords on their servers and restores them to your phone if you do a reset or get a new phone. You are just as much at risk from Apple's services as you are from Microsoft.
Mandatory updates are to ensure everyone has the latest security patches. Microsoft will not provide product support unless the version is current and this is a way to prevent security breaches and virus propagation.
The keylogger issue is no more of a problem than on Android or iOS. Any time you are typing in the search boxes you will see suggested terms start to appear. They are all sending keystrokes under certain conditions to try and predict what you are trying to do.
The telemetry that is collected under the Basic setting is not going to contain any personal information. If you read the description you will see that only under option 3 will anything be sent that would be personal information.
Real time protection is another item to try and prevent viruses and malware from causing problems. I'm not sure on this one, but I would assume like in Windows 8 you could install some other antivirus program like Norton and it would take the place of Microsoft's product.
Someone went to great lengths to instil fear of Windows 10 in people by creating that picture. It is full of half-truths and twisted facts.
