Contact on a Force Play - FED

[cshs81]

What are you looking for when there is contact between the sliding runner and the fielder with the ball on a force play in order to determine if the contact is legal? I realize this is a broad question.

I've read the various threads regarding FPSR and understand the sliding portion of the rule. However, what is legal in regards to the runner's use of his arms in making contact?

If he's sliding with his hands up in the air in what appears to be a normal slide and the throw makes contact with the arms, is it interference?

If the runner's elbow dislodges the ball from the fielder's glove on the force play , its it interference?

Is contact on a popup slide interference?