Answers to the questionnaire for Generic Sensor API can be found here.
No.
No.
3.3 Does this specification introduce new state for an origin that persists across browsing sessions?
No.
No.
3.5 Does this specification expose any other data to an origin that it doesn’t currently have access to?
No.
No.
No.
Yes.
3.9 Does this specification allow an origin access to aspects of a user’s local computing environment?
Yes. If user agent has permission to access proximity sensor, the API provides means to check if sensor is available within user’s local computing environment.
No.
No.
No.
No.
Specification does not restrict access to a particular mode, nor work differently. However, this can be revisited when privacy mode would be formally specified.
No.
Yes.
See: Security & Privacy section.
No.