Personally I just play secret missions until I have the resources for what I want, are resources common as a reward? no, but secret missions are hardly rare.
I mean I faintly resent having to play the world map missions, initially I play 2 to get my tier orbs, but after that in my cost benefit analysis they offer me nothing, so when eventually I am forced to play them to progress it is grating.
On the topic of people trying out spells, personally I change my main combat spells at the start of each new continent, and it makes each continent a lot more interesting, so i see no reason why players should be encouraged to try all the spells at once, if anything i'd suggest a pop up saying
"The world continues on forever, don't feel rushed into trying out all the spells now, you have a lot of time and opportunity to experiment"