Are your PC's pregens or custom built by the players?
If custom you might have an optimization problem like I have in my game where combats are hard because your party isn't doing the expected damage.
They're custom built, and not particularly strong. I'm letting them rebuild from scratch now that we all have a better idea how the game plays.
For the game to work well they need to trust that you will be constructing fair and balanced encounters, you need to trust that they are not going to abuse the situations.
Thanks for all the tips

"Oh I finally figured out what 1d12 means..."

They sound as if they view taking extended rests as save scumming, when they're not.
That's a bit harsh... I never actually explained extended rests vs short rests to them during the game (because I hadn't read up on the rules about them at the time, myself).
So anyway, that's why I'm going easy on them. I think they deserve to get their dailies back given the fact that I'd made so many mistakes with the rules ("So you can move and attack diagonally, lol?") - it doesn't make a lot of RP sense, but yeah, we're just starting out. I think it's ok to make some mistakes.
My initial question was more for future reference than our current game, where I just feel like I've gotten myself in a bit of a hole.