Spawn has 4 walls both with warp pads leading outside. There is a glass wall (im assuming) to prevent spawn campers going in and out of spawn.
Now this is what I see and I get completely confused.

The wall is there to prevent players from keeping going in and out of spawn aka "spawn sitters / campers" or w.e. So WHY is there a safe spot outside the wall. It completely defeats the purpose of the wall. There also used to be ONE warp pad which lead out and people would use that to make people fall and die or w.e and that could be fixed.
Here is what I'm suggesting for this spawns design. First off I feel there should be 2 Regions. 1 to protect some land outside spawn building and 2 to protect the center part where there is no PVP. Doing this would make it fair gameplay and would prevent the spawn drop kills.
Another is to drop the wall of spawn and REDesign on how it works. I made a quick image to show you how it could work.


The stain glass represents different aerclouds. This would make it so that players cannot use smart moving to get Back into spawn and players are not able to just sit there at the drop and attack someone before they fall down. It also would allow players to pick multiple directions out of spawn and still have fair game. Rather it be North West, South East, North, East, West, WeEast (lol jokes).
These changes would make spawn somewhat more logical and better for the pvp side of hardcore.
Other Changes I would like to see done to hardcore would be:
-Herbalism Hoe Right Click Ability MCMMO:
Giving us this ability would allow us to make mossy cobble, Mossy stone brick, and grass if we wanted.
-Blue Berry Bush Generation / Orange Tree Generation:
Knowing how the map is only 1k/1k I think that this could be just added by someone flying around placing them but if part of the world is not generated then aether biomes should allow us to collect them.
-Colored AerCloud Generation
Colored aerclouds could be a big contributor to traps and travel within hardcore. Adding different clouds could help out. Here is the idea on this:
Red, Orange, Tangerine Aerclouds - Nether / Volcanic Biomes
Lime, Green, (Rare: Plasma) - Jungle
Fuchsia , Purple, Pink - Extreme Hills / Plains
Jade, Navy, (Rare: Royal) - Rivers / Ocean Biomes
Could be too late for these to be added but would be nice for newly generated lands. This could also probably be added to more biomes than I mentioned but I didnt know all them so I just wrote what I knew.
Potion of Undeath:
Adding these to dungeon chests would be nice. Only reason I'm mentioning this is because I'm not sure blazes spawn in hardcore and I'm not sure if its possible to obtain these. Would help us if we wanted to give our team mates exp that we have to help them and to reset spawners (if we wanted). Oh and it would help with villager trades.
Hardcore Achievements:
Some achievements that we could get in hardcore that would only give us money so we wouldnt get items but some nice achievements would be cool.
Golden Skyroot (if they arent already put in): I'm not sure if these spawn in the aether biomes but if they dont it would be nice to get them added so we could make darts.
Bed Fix:
I feel beds should be fixed. When you get into hardcore and you sleep in your bed then every time you die you spawn back at your bed. Until you log off then you have to go back and reset it. Another thing is that if you go to spawn and come back you then have to reset it. Also I feel if EVERYONE is sleeping in a bed on hardcore it should return to the normal function where if everyone sleeps it turns day. Could be ruined by one person not sleeping but it would least give a chance.
Cursed Blade:
Rare chance of being able to obtain a cursed blade from killing players (ONLY IN HARDCORE). Maybe a 1/10,000 Chance of getting one. Chance is reduced if a player just keeps killing the same few people over and over again (aka spawn killing). Or making it so the further out you are from spawn the greater the chance is to obtain one from a player death.
Example:
Direct spawn: 1/200,000
500 Blocks away from spawn: 1/100,000
1000 Blocks away from spawn: 1/5,000
Hopefully you like some of the ideas