Blocking the base

[bossman72]

R1 stealing. F6 sets up to take the throw from F2 straddling the bag with his left foot blocking the base. R1 slides and would have beat the tag, but he slides right into F6's leg and never gets to the base and is tagged out.

Anything wrong with this play?

Conversely, what if F3 blocks the base at first when receiving the throw on a pickoff?

Are any of these different than when a catcher blocks the plate on a play at home?

A couple of these plays came up this year (luckily none were my call) and i'm not too sure of the exact ruling to be consistant with my calls.

Please also mention how obstruction comes into play in these scenarios.

Thanks a bunch!

bossman72