Situation 2

Yes, this should be called as a "Delay of Game" penalty.

What guidelines should be followed in allowing a player to catch the puck and immediately drop it?

A player is not given three seconds in which to drop the puck nor may he take one or more strides while holding the puck.  He may not fake as if to drop it somewhere else. The motion of catching, then dropping the puck, must be virtually one continuous motion. While no specific time is given in which to drop the puck, the move to get rid of it must take place immediately. Rule Reference 615(a).

In addition, “dropping” does not imply “throwing.”  While a player may bat the puck the length of the ice with his hand, he may not catch the puck and then throw it away from his body. The puck must be dropped to the ice in his immediate vicinity.