Among all kinds of billiard games piramid is the most popular in ex Soviet Union's countries. Concerning piramid as a sport there are three different games and we have all kinds of tournaments to be held in these games. 1st game: let's call it Free piramid. In this game each time you come to the table you are free to choose which ball you use as a CB. Two other games let's call them Combined piramid and Dynamic piramid. Playing these games you have a CB as in pool which is differ in color (it's the only colored ball among 15 white). In all three games the goal is to have 8 balls to be pocketed to win the frame as in one pocket game. In all games you are allowed to pocket the OB like in pool or snooker or pocket the CB making a billiard. Each game has its own tactics founded on the rules of the game. For example in dynamic and combined piramid each time you pocket the CB you can take any OB from the table which counts for you and start with CB in hand but in combined piramid playing from the kitchen area and you are allowed to pocket an OB and the CB. In dynamic piramid you can start with the CB anywhere on the table but allowed to pocket only an OB. That is when it comes to the goal, rules if to be very short. Of course as in any other billiard games there are certain rules for an open shot, the shot to be correct (when it comes to safeties because there are a lot deffensive play especially in combined and dynamic piramid), penalties and so on.
When it comes to the match in this video the girls are playing free piramid and Diana Mironova is the most talented and successful player whith excellent technique I have ever seen. She's the one and only and she played in the final of WC Free piramid for women for the first time at the age of 12 years old. Now she's 21 and seven times the world champion. She is the great example of many things to follow.
Now let's come back to the questions.
1. I've already covered.
2. On the break you have to pocket the ball (any ball but of course it is easier to pocket the CB) or to have three object balls to hit the cushion or two balls hit the cushion and the third across the center line. The rules for the break shot were changed in order to make the game more offensive. I remember the times when they were different.
3. Yes the pockets are fairly small counting the balls are much bigger than in pool. The balls are 2.677" and weigh around 10,23oz. Corner pockets are around 2.95" sides are around 3.19". And the jaws are different so when you intend to pocket the ball which is closer to the cushions the pocket becomes so small you have to be a very good shooter in order to pocket it and yes better use some power when the size of the the pocket equals the ball's size. When it comes to pocketing the CB it's another story of course when you have to know and feel the speed, cut angle and english for each shot.
4.When it comes to the cues standard length is 63" weight around 23,8oz - 25oz. 12,7-13 mm at the tip and 28mm at the butt cap. The length of the shaft and how much at the joint depends on the construction of the cue. Most players prefer two pieces cues almost equal split but usually the shaft can be longer just a little. It is just more comfortable to travel with. But there are ones who prever 3/4 cues like in snooker or one piece cue. Three pieces cues also were fairly popular in the past. Concerning the construction, design and materials used and so on this game has its own story and history to be said. And that is a long but very interesting story. As in any other billiard game there are some very known cuemakers making the cues which are real pieces of art. And to say the truth when it comes to the cue building I've learned a lot by looking through the whole building process, construction used and so on in this game. It's not only very interesting but also helps me what could be done better building a pool cue. I remember the time when I've bought my second Prather cue Dan Prather was interested in construction used in piramid cues and exchanged his experience with one of the ukrainian cuemakers and my teacher Jorgen Sandman a good friend of him helped with this.
I hope my English is understandable enough.