My ideas
1. A new world, called pangea. where there are some unique animals, also some indians that can attack you. You form this portal by making a 4x4 square out of grass blocks and then drop into the portal a eye of ender
2. Different speeds on different blocks, You run the fastest on gravel, you run the slowest on clay. Different speeds on different blocks, Like the horse
3. Option to turn of rain particles/weather
4. Add a lot more villager trade options with different items/tools
5. Flint tools, Same regular recipes but using flint, the sword will do 5.5 damage (Better than a stone but worse than a iron). and they can mine a bit faster than stone. Also they can mine redstone and gold ore
6. Honestly, a couple birds in the sky, and some birds nests that if you break you get sticks and string.
7. A New enchant called butcher that you can obtain on a sword, lvl 1-3. You can kill peaceful mobs faster. Also a new enchant called slayer, lvl 1-5. Where you can kill any mob faster.
8. Some intense wether. Tornados that can wreck your base, volcanos that can explode,cyclones, microbursts, etc
9. Clothes to warmth you. If your in a snow biome you may have a warmth meter, If it goes down then you start getting frostbite (Getting weakness forever until more warmth) Then if you go down lower you get hypothermia, then start to slowely take damage
10. Thirst meter. If you jump into a river/lake you get some thirst. If you jump into a ocean (Salt water logic, even though minecraft has no logic) you will loose thirst 3x as fast for 30 seconds. Also you can create bottles and catines. using a bucket, and 4 wood in a hopper shape
11. More boss mobs
Those are my ideas...