well I can tell you right now that number 3 will never be ... right now you need to spend 900 kobans for epic pachinko (or try your luck) to get one girl and it may not be event girl so you must try again ... so here is no way that they will add 100% chance event girl for just 500 (maybe for 1800 or something like that). And number 6 is the same ... it is much better for devs to just add girls to epic pachinko (if they add more girls to epic pachinko people will have bigger chance to get them in events instead of event girls and will have to try another spin). Number 4 is the same problem ... why should they give us scaling gear when they want us to switch it as many times as possible (most of the good gear in shop cost kobans). And number 2 will not happen because then people would want to be able to chose girls in events and so on. Most people would like to get added girls from events permanently but devs already said that they will not do it ... right now we get them in epic on anniversary event and we are not sure if it will happen again next year. So all in all only thing that have chance is your suggestion number 1 in my humble opinion. (btw sorry for chaos in my post but you will get it in the end)