2 Will surely happen over time. They add new story stuff every now and then, don't remember when Chapter 10 was added, but it wasn't in when I started.
I would love to have some more options for getting the event characters, they used to allow people to get gemstones by fighting incredibly difficult bosses, but they removed that option before I ever got the power to join in. Honestly it's one of the reasons I originally liked this game and got into it. It was nice that players that had bad luck and small wallets could actually enjoy the event characters too by working hard for them, rather than selling both of their kidneys for a single Foxfire Fubuki.
I'm sad to say, four will probably never happen. If players can trade for the characters they want, then they don't have to dump as much money into the gacha. However if it does happen, I've got a Zwei that I'd be willing to trade for just about any SR.