Well I can answer 1 and 2.
1) Here is an older implementation of how to interact with obi partciles in VR. It'll get you in the right direction anyway, never used leap. This snippet uses pins, where handles would be better since the actor will never physically effect the controllers. If for the range grab, you want the cloth to go to you, you'll need to lerp each particle somehow so it doesn't snap to your hand. Doing so the cloth will go crazy.
2) Yes, if you change the mesh you will need to reload the collider and obiCollider. Obi now uses a new collision system where you add an obiCollider to objects you want to collide with. ColliderGroup is deprecated.
1) Here is an older implementation of how to interact with obi partciles in VR. It'll get you in the right direction anyway, never used leap. This snippet uses pins, where handles would be better since the actor will never physically effect the controllers. If for the range grab, you want the cloth to go to you, you'll need to lerp each particle somehow so it doesn't snap to your hand. Doing so the cloth will go crazy.
2) Yes, if you change the mesh you will need to reload the collider and obiCollider. Obi now uses a new collision system where you add an obiCollider to objects you want to collide with. ColliderGroup is deprecated.