1) A more balanced economy. By this I mean a lot of the spawners in shop are overpriced and a lot materials are underpriced such as iron which only sells $15 each.
2)Void chests(Kingace explained it)
3)Sell wands. This an item that allows you to sell in a chests by a simple left click.
4)The end. The endstone should be sandstone because it will make it easier to trench
5)Disable PVP related mcmmo.
6)Lava walls could be blown up without stacking any sand. This will make new cannoners life easier if they fok up the shot on lava wall and it creates a block infront.
7) Head system. When you kill a player, you receive a percent of their balance.
8) NCP'S. Ncp's are like players but without any player controlling it. People could buy it on the shop for a million or whatever price u choose and place the egg(or whatever) near the spawner and it will afk it 24/7.
9) Increase player power.
10) Faction Challenges. Example: "Challenge is to place 60000 netherrack" so when baseworking people would use nether rack and receive something in exchange.
11) Genbuckets should be cheap(Xone is retarded) and disable normal way of genning walls(Lava and water) because it lags the server.
12) Allow shematica for base work, most servers now allow printer to make trays, filters,etc.
13)Allow the suggestions gunfire made above
14) Making gapps more rare. Seriously gapple pvp is aids. Takes 20million years to kill anyone plus every "big" server does it and i think jartex should do it(also cus im pot pvp g0d)
15) The three durability thing is bad. For example, you make a noob base in the beginning in the season and then when you make your big base you have 2/3 durability left. So i think you should change it to something like it takes certain amount of days/hours to charge the spawners up to 100% and if you mine it, it will reset.
16)Improve the cannoning and server performance(making clear lag more often, instead of things lurking on top of hoppers make it instantly go into hoppers and dont make it flow instantly, slow the hoppers down)
17) Extra drops. By this I mean like when creepers who die, will drop tnt, etc.
18) ./rankup or spawner levels. For rankup, each level unlocks you a spawners(Level 1
ig spawner, etc) or spawner levels( you would click on the spawner and then there would level 1, 2, 3 blah blah and each time it will increase spawner productivity).
19)Sell all or sell hand. You have to admit selling your loot is aids so this will make it easier.
20)New anti cheat.
There are a lot of ideas above, I hope at least some of them get added ^_^