Good morning,
Greetings from Venezuela, full support and affection for the project.
First of all, to say that at this moment many of the people who are part of this wonderful project have already participated in many games and have knowledge about what mounts imply and the diversity of uses that different online and offline games have given them. This needs to be said by the following.
1.- If a system is implemented where we can by means of objects, equipment, food, herbs, potions, etc. increase the speed of our mount, in my opinion, it would exercise a key point in favor or against the PVP system, this because it can be used or to capture objectives faster than the rivals or to do chases, obviously for those who have a better mount it will be a plus but for those who do not, I do not think it is so pleasant. And here it is important to note that it also depends on whether these objects, equipment, herbs, potions, etc. can be obtained on a regular basis or only by paying real money, because if it is with real money it would become a P2W method. So it's the least I think the community at large wants.
2.- The fact that your mount can perform attack skills, I think it should be treated with great care, because as indicated above it can cause imbalance in the PVP system, I think the best thing is that if this system is implemented only and exclusively those skills of attack only serve in Questing PVE but NOT allowed in Dungeons or Raids and not in PVP.
3.- I think that the saddle breeding system would be an excellent idea, just as the saddles come from different natural sources but all within the environment that surrounds medieval fantasy, as I said in another Post, I don't think it is positive For player immersion see Flying Pink Ponies, or Pokemon cars, for example.
4.- It can be positive for the company on a monetary level to take advantage of this system to implement special and exclusive decorations for the mounts in the game store, such as chairs, battle armor, decorations for the wings (in case of being a flying mount ) that cannot be obtained by playing, only paying, this in order to motivate the player who wants to invest money in the game. But it also allows F2P players to obtain accessories of a slightly lower category or exclusiveness by playing the game. Of course, it should be noted that these accessories are F2P or paid, they must not contain active or passive bonuses that benefit the player to avoid imbalances in the game at all costs.
That's my opinion.