Quick question: When under the heroes' control, can Splig move normally or does he only recieve 1 movement point per move action, as he is treated as a hero figure??

Quest rules that say "heroes" only apply to actual heroes, not other things treated like heroes (familiars, allies, or in this case, Splig). Quest rules that say "figures" would apply to heroes, monsters, familiar figures (the reanimate but not a stone or skye).

Thanks for clarifying Zaltyre!