How to Preform: Focusing my chakra into the rain that falls down, I focus on the drops that fall in and around the area where you stand, using my chakra to slightly alter the properties of the rain drops so that they become thick and sticky. As the drops fall down on you they stick to your clothes and bind you to your spot, immobilising you.
Advantages: Since your opponent is stuck to the ground he will be an easy target for further attacks.
Disadvantages: The opponent needs to be in contact with the ground to be stuck to it and the rain drops need to touch him to be effective.
How to Defend: Since the rain comes from above I would suggest using an earth technique to block the rain
Other: Is the opponent only stuck to the ground or is he totally immobilised ei, he can't make any hand seals any more
How to Preform: As the rain keeps in falling down, I focus my chakra into the rain and create an exact reflection of myself.
Advantages: As you said you can use it to confuse your opponent, creating an opportunity to attack him.
Disadvantages: It's only a reflection, so besides a distraction it can't do anything else
How to Defend: It's no attack, so you can't really defend against it.
Other: Does it work like a kind on mirror, so the reflection moves in the same moment you do, or does it move independently from the user?
As for creating the rain, is there a technique one can use besides Rain Tiger at will or do we just say that we focus our chakra in the clouds to make it rain, cause that sounds a bit stupid...