Man, this low stamina cap is a killer. If I don't check on the game every two hours I'm massively wasting stamina.
What are you at now anyway?
We all know it's entirely by design and considering the pull rates for rare units and the generally dismal costs ... you might start to get a picture of Gumi as something of a greedy company. I think it would be accurate, except I also think they're making a lot of money and they're practicing the great art of 'because we can.'
Never give Gumi your money and expect anything but heartache. Assuming they even give you your lapis.
All this said, the babysitting goes away in about a month or two, maybe less. Once you get into the higher 30s on rank it gets easier and you can fuck around for 4 hours instead of every two. Wasting NRG at the bottom ranks is basically impossible, so don't sweat it.
Once you get to lvl 50 and higher -- also around the time you'll probably start TM farming, depending on your team -- you'll really be in great shape. (TM farming changes the entire feel of the game and relationship the gamer has with it. It's different and neat and comfortable, unlike the stress of the early meta)
Edit: you can mitigate a lot of this problem by really going all-in on high rank exp rewarding events. I can't remember which event it was but somewhere after Halloween one event rewarded 600 rank exp per battle and a lot of us went up something like 25-30 levels in a couple weeks. It was glorious. (also lapis comes with each level, so...)