Your Tolarian Terrors are generally used to trade, but they can pivot into a racing role, forcing your opponent into awkward blocks
It does not, for example, change when you may activate abilities that can be activated "only as a sorcery." The last ability cares only about the amount of mana that was actually spent to cast the spell, regardless of its mana cost
A lot of the smaller, hard-to-block creatures are elves and there is obvious tribal synergy
However, if there are any additional costs to cast it, the mana spent to pay those costs counts
You can quest with him and return a Merlin, Goat back to your hand, giving you four lore instantly, and allowing you to play the Goat again to immediately gain one more, and another when the Goat leaves play
No matter what youre interested in playing or building a deck around, Commander has something for you