First house rule from my P2e remaster game, offered for your review.
Spell Slot Heresy
Since Pathfinder is balanced at a per encounter level, per-day limits on daily abilities are largely only kept around due to tradition. And tradition is just peer pressure from strangers, I don't see a good reason to follow it.
Any spellcaster can recover spent spell-slots with a one-hour activity, as noted below, while characters with focus points can recover them during combat.
Recover Magic
Traits: concentrate, exploration, manipulate
Requirements: You have expended a spell slot or used some other once-per-day activity
You spend one hour to recover your expended magical power.
During such time you may not work on any other activities or actions or be treated for wounds. At the end of the hour you regain spell slots or once-per-day abilities as per your daily preparations. If you have cast spells from a wand or staff, the item also regains any expended uses or charges.
If you are a prepared spellcaster such as a cleric or wizard, you may not replace what spells you have prepared for the day.
Refocus (1A)
Traits: concentrate, flourish, manipulate
Requirements: You are missing at least one focus point.
You take a moment to perform some deed to restore your magical connection, such as touching a talisman, speaking a phrase, or simply taking a breath. Doing so restores 1 Focus Point at the end of your turn.
EDIT: For the record, please presume the above is all released under the ORC license as a derivative of Player Core 1.
Spamming Rebuke Death every other turn also completely shatters any difficulty.