Idea A few ideas

1v1:
When someone joins a 1v1 it pops up in the action bar, like in ctf you can toggle where it displays the messages of the flag (captured,steal,recovered). Maybe there could be a command like this but /1v1display (actionbar,subtitle,chat) toggle. This would mean you could have it in chat rather than the action bar. There could also be a command like this but for deaths/kills (/deathdisplay). Also /1v1invites toggle (means people can't invite you to a 1v1). Also add a bonemeal that when right click opens the gui for 1v1s (/queue1v1 takes too long to type)

Kills:
In the the new kitpvp alot of the time people still you kills, say you get 87% of the damage and it's an assist, you will get 0.87 kills, if you get 32% of the damage and it's an assist you get 0.32 kills. But if you get say 59% of the damage and you get the final kill you will get 1.59 kills. This is just an idea.

Perks:
I think there should be a way to upgrade kits with each level (like in hypixel's skyclash), maybe you can have 1 perk per kit and there are 10 perks you can have (5 for each kit, some will be for multiple kits). Everytime you level up, you get 5 random perks(you might get 2 of the same), you can upgrade a perk if you have duplicates.
Level 1 Perk (1 perk)
Level 2 Perk (2 perks)
Level 3 Perk (5 perks)
A few ideas of perks are:
Regenerate - You will get regen 2 for 5 seconds after you get a kill.
Gravity - You will get jump boost 3 for 5 seconds after you get a kill.
Strike - When you right click your weapon twice it will send a bolt of lightening that will do 4 hearts true damage and 5-7 blocks of knockback (17 second cooldown)
Tank it - When you right click your weapon twice, you will get resistance 2 for 7 seconds (21 second cooldown)
Viper - When you right click your weapon twice, anyone in a 6by6 radius will get poison for 4 seconds (19 second cooldown)

Clans:
I think having clans would be really cool, you will get kills for your clan and those kills will be turned into points. There are 3 roles in clans.
Owner - Can do all the commands (can't do ones with a ^)
Manager - Can do most of the commands (can't do ones with a *)
Member - Can do hardly any commands (can do ones marked with @)

Here are some commands:
/clancreate (name) * - creates clan
/claninvite (player) - invites player
/clanpromote (player) (rank) * - promotes a player
/clanmotto (motto) * - changes motto of clan
/claninfo (name of clan) -info about clan(members, name, description, points)
/clanleaderboard - list of top clans based on points
/clankick (player) - kicks player from clan
/clandisband - disbands the clan

Maps:
When someone accepts your 1v1 invite you will be put in a small 5by5 block thing with a GUI popped up with all the maps as well as a paper which is a random map, the players will then click on the map they want, for the map to be chosen you will need both of you to select that map. When 1 person has selected it it will be enchanted, when 2 have the 1v1 will start.

Events:
I think the events are a bit stupid if I'm going to be honest, they don't make many sense. An idea instead would to have a supply drop every 3-5 which is an enderchest, when the supply drop spawns a firework will go up where it spawns. Whoever right clicks it will get the items, there are 1-3 items (for example you might get 4 soup, a speed pot and a crapple). A few ideas for items are:
Crapple
2-5 soup
Speed pot
Strength pot
Ender pearl
Jump boost pot
Regen pot
1-3 tnt (automatically invites after being placed)
If you die with an item you will respawn with it. This will happen until the next supply drop where you will lose the items you still have for good. The supply drop could be called something more unique such as a BrawlChest or Supply Brawl. It will say 10 seconds before it arrives that it will spawn (BrawlChest arriving in 10 seconds), it will then count down from 5,4,3,2,1. Every second (from 5 seconds) a firework will go up but it will gradually get bigger until when it actually arrives there is a large one that can be seen from across the map. When it arrives a message should say in chat (BrawlChest has arrived at (co-ordinates), open it for bonus loot!). The BrawlChest should be an enderchest with a Diamond Block under it with gold surrounding it, quartz slabs should then go up to it in a star shape.

 

You will still be able to kill each other and also maybe a max of 5 in a team?

 

I guess that is true. I added 2 more ideas (maps and events).