Here some of idea that may help about shortlinks :
for every 5 training complete 1 shortlink
and about energy its abit low ... i think u need to implant a leveling system for the player as well , for each level u gain 1 more energy
also u can add chest or box for sale that divided by 3 rarity
about questing and other stuff i have some idea as well but its waaaaay hard to be implanted in the game for now but i can share it