Played since beta opened on PS3. I do not recommend playing open-world and/or end-game content without an SSD, because it won't be fun. You often won't see objectives/monsters and on rare occasions it can get laggy. Also of note: I pretty much exclusively healed until I quit a while ago.
Time spent engaging kids is time well spent I think. Whether it is reading books together or playing video games or throwing a baseball around, I have a hard time believing that type of interaction can ever be a bad thing.
I think the keyword here is like Dave mentioned, "together." If you play games together with your kids or not is probably what matters the most. But yeah too much of any one thing is almost always bad.
It's been a long time since I've used any sort of RPGMaker software, but from what I can tell, Engine 001 looks pretty decent/easy, is free, and works on MacOS. Good luck, and have fun in your quest to make quests! :P