Origin is the worst piece of shit DRM ever (edit: second worst, forgot about GFW Live). I will never use it or play another game that requires it, unless there are some drastic improvements.
I've never caught GWFL scanning my hard drive for pirated copies.
We have been over this. This is not what Origin does.
Even if it did not, I would still not install Origin until the EULA wording that supports this sort of activity on EA's part was removed. After what they did with ME3 (which was brilliant, btw; they waited until we were hooked on the story from the first two, then hit us with the Origin hammer for the conclusion), I would be very hesitant to buy any games on it as well. It would not surprise me if they reversed it, got a lot of people to buy their games, then returned it to its original condition, thereby requiring the customers to keep it installed if they want access to the games for which they already paid.
Call me a conspiracy theorist, but in light of EA's behaviour over the past 10 years or so, I would not put it past them.