Guiding planes are flat, polished surfaces on the abutment teeth that guide the RPD into place. They are crucial for the predictable placement of retentive elements such as clasps and for ensuring that the forces are transmitted along the long axis of the teeth, minimizing horizontal movements. Additionally, they help in the overall stability and function of the denture.

Excessive vertical dimension may affect all of the above: encroaching the freeway space, proper centric relation, proper retention.

The Bull rule pertains to the concept of occlusal balance during lateral movements in dentistry. It suggests that certain cusps may need to be adjusted or ground to achieve a balanced occlusion, particularly in the context of removable prosthodontics or fixed restorations.

Ante's rule (option 1) relates to the relationship between the anterior and posterior teeth in occlusion. 

Articulators are classified into arbitrary positional and functional by Boucher.
Arbitrary positional articulators hold the mandible in a pre-determined, fixed position that does not necessarily represent the patient's true centric relation or functional movements.
Functional articulators, on the other hand, aim to simulate the patient's individual centric relation and dynamic movements of the mandible, allowing for a more accurate representation of the patient's actual occlusion.
Boucher's classification system is based on the type of articulation and the way it records and transfers the patient's jaw movements to the dental casts.