The best creature type is hard to define, but some metrics can be used to narrow it down: If youre looking for creature types that make good creature-focused (i.e., typal) decks then you probably want goblins, humans, or elves
You may cast it without paying its mana cost if its a spell with lesser mana value
Death's Shadow decks still sometimes run this card, though
Lone Riders last ability wont trigger if you havent, even if an ability triggering at the same time will cause you to gain life
Similarly, of the hundreds of cards that Mark Tedin illustrated (including ones paramount to the narrative lore of the game), its the Chaos Orb that was his choice for the banner of his website
You definitely need to have a lowish curve to take advantage of this, because you need to hit two creatures when you cast it for it to be worth it -- but I think that'll be the case for most decks