Any combination of evocation, divination, enchantment or necromancy does just fine, the only two schools you really do not want to ban are conjuration and transmutation, maybe illusion, though lots of potions out there to become invisible. Displacement is hardly neccessary on a non-tank and the Bard does not get many spells per day anyway.I'd rather have a spell that gives a significant boost to the entire party than Displacement. That early you also have no need for Displacement, Blur is sufficient. Earliest would be act 2 against Hodags
If you say so. For my party, Displacement and Haste are 10x more valuable than Good Hope. Displacement in particular is a game-changer for my two tanks. As soon as its available.
Displacement is 2.5x better than Blur, Blur doesn't cut it against tough targets.
Good Hope is incredibly efficient. It is a fire-and-forget improvement to essentially every important stat except spell/ability DCs for long enough to run out of most other resources while using few resources itself. With the possible exception of Womb of Lamashtu (given the wandering and relatively low level of Good Hope at that point), I don't think there is a single dungeon in the game that requires more than two extended castings of Good Hope. Lesser rods of extending go to sleep at night hoping they'll modify that spell in the morning.
Plus, does the amazing duration of Heroism actually come into play if you rely heavily on Displacement and Haste? Unless you push through a lot of fights without them you'll be out of 3rd level slots long before either Heroism or Good Hope wears out. In which case they effectively have the same duration, except Good Hope buffs everybody. In the other case, the more fights you push through the greater the relative value of one casting of Good Hope to one casting of Haste/Displacement. Haste and Displacement are great spells, but by 9th level every Bard should have at least 4 3rd level spell slots. Surely one can be spared for Ultimate Pep Talk.