In the beginning, while I was still short on AP I wanted to play the heck out of this game yet could not, since just two 50 AP mission pretty much made me stop playing for half the day.

Now I have almost 280 Stamina and units strong enough to clear the event and farming mission so taking it easy is how its best done.
After all - what else can you do with a game that limits your playtime ?
Get in, play till you exhaust all your stamina, and then go do something else for the day. Log in later and mash out rest of the daily. Done
Once you "absorb the fact" (not just understand, you actually have to get in the pace of it) that the "progress" in this game (since there is no real story to progress) is paced around the events, and thus its rather slow (they change every 2 weeks after all), the nervous "hustle" compeling you to "do something" in the game, you feel at the moment will gradually fall off, and you´ll be able to enjoy if for what it is.
At least thats how it feels for my when I play games of this (browser) type.