When a player performs a quest for a Villager, the player's reputation with that Villager improves, allowing the player to spend fewer emeralds when buying from the Villager....
You are right about the GUI, but regarding quests being too easy, consider that anything in your statistics page can be a quest: Kill some withers, mine a bunch of endstone, etc.
There are plenty of ideas that Mojang has said that they don't plan to add, such as the ones on this official Previously Considered Suggestions List. Even so, are there any such ideas (or ideas generally viewed as "modded" by the community) that you think would fit in vanilla and should be added regardless?...
When an item has the Materialist enchantment, it can be repaired in an anvil with that item's "repair material" as many times as the player wants to do so, without the anvil's "too expensive!" being a barrier....
If an empty Glass Bottle is put into the fuel slot of any variety of smelter, and it has at least 7 experience points stored in it, then seven of those points are used to turn the Glass Bottle into a Bottle o Enchanting which then gets moved to the smelter's output slot.
This suggestion is to allow hoppers and droppers to put enchanted or damaged items items into a grindstone, and to allow hoppers to pull out disenchanted or repaired items out....
This idea is simple, if I put an Enchanted Book with Bane of Arthropods into a Chiseled Bookshelf near an Enchanting Table, then the Enchanting Table will not generate enchantments which include Bane of Arthropods....
The first issue can be solved by giving Chiseled Bookshelves a tooltip, or a different name ("Anti-magical bookshelves"?), or the first time the player obtains a Chiseled Bookshelf, they are rewarded with a written book telling how to use it.
The second "issue" is intended behavior. I think this is a good way to solve the issue of enchanting being too RNG heavy.
Stone type blocks in minecraft have always had a upper hand when it came to block varienty compared to wooden ones; they can come in the form of polished, bricks, pillars, cracked and more recently tiles....
Villager Quests to Earn Discounts
When a player performs a quest for a Villager, the player's reputation with that Villager improves, allowing the player to spend fewer emeralds when buying from the Villager....
What "rejected" ideas would you like to see in the game?
There are plenty of ideas that Mojang has said that they don't plan to add, such as the ones on this official Previously Considered Suggestions List. Even so, are there any such ideas (or ideas generally viewed as "modded" by the community) that you think would fit in vanilla and should be added regardless?...
Dandelion Honey, Poppy Honey, Allium Honey, etc.
This idea is to add to the game as many varieties of honey as there are flowers....
Materialist, an early-to-mid-game Mending Side-grade
When an item has the Materialist enchantment, it can be repaired in an anvil with that item's "repair material" as many times as the player wants to do so, without the anvil's "too expensive!" being a barrier....
Tinted Stained Glass
This suggestion is to add 16 new blocks which are opaque to the light engine but rendered transparently....
Endermen don't grief near Chorus Plants
In the vicinity of a Chorus Plant, Endermen feel sufficiently at-home and relaxed that they don't feel the need to pick up or put down blocks.
XP Extraction from Furnace, Smoker, Blast Furnace
If an empty Glass Bottle is put into the fuel slot of any variety of smelter, and it has at least 7 experience points stored in it, then seven of those points are used to turn the Glass Bottle into a Bottle o Enchanting which then gets moved to the smelter's output slot.
Cook Bottles o Enchanting into empty Glass Bottles
This idea is to add Furnace and Blast Furnace recipes to convert a Bottle o Enchanting into a Glass Bottle, plus 7 or 8 experience points.
Automatable Grindstone
This suggestion is to allow hoppers and droppers to put enchanted or damaged items items into a grindstone, and to allow hoppers to pull out disenchanted or repaired items out....
Brush the Eye of Enders out of End Portal Frames
Using the new archeology Brush on a Filled End Portal Frame block turns it into an Empty End Portal Frame, and causes an Eye of Ender to Pop off....
Redstone Elevator
The Redstone Elevator is a new shape-changing block for moving mobs, players, and other entities....
Enchantment "deny list" for Enchanting Table using Chiseled Bookshelves with Enchanted Books
This idea is simple, if I put an Enchanted Book with Bane of Arthropods into a Chiseled Bookshelf near an Enchanting Table, then the Enchanting Table will not generate enchantments which include Bane of Arthropods....
OC Carpented planks; A new wood block to add varienty to wooden builds and a wooden equivalent to stone tiles
Stone type blocks in minecraft have always had a upper hand when it came to block varienty compared to wooden ones; they can come in the form of polished, bricks, pillars, cracked and more recently tiles....