Issue 1: Tab Completion
I've used for example /tp d3 then press tab and It didn't complete my player name [username: d3ath2005].

Issue 2: Kit item tags
Is it possible to add an item to a kit containing tags such as Unbreakable, Hidden Flags(Hide item enchantments, Hide unbreakable, etc.)

Any help would be appreciated.

Issue 1: Duplicate of #1287.

Issue 2: I believe you can use NBT for that: {Unbreakable:1} (Make sure to put it at the end of the item definition)

@SupaHam
Issue 1: Feature hasn't been implemented yet.

Issue 2: How could I add this tag in the configuration file?

kits:
  Starter:
    delay: 86400
    items:
    - DIAMOND_PICKAXE 1 name:&eStarter_Pickaxe dig_speed:15
    - IRON_HELMET 1 name:&eStarter_Helmet
    - IRON_CHESTPLATE 1 name:&eStarter_Chestplate
    - IRON_LEGGINGS 1 name:&eStarter_Leggings
    - IRON_BOOTS 1 name:&eStarter_Boots

Make sure to put it at the end of the item definition

@md678685 - Like that?

kits:
  Starter:
    delay: 86400
    items:
    - DIAMOND_PICKAXE 1 name:&eStarter_Pickaxe dig_speed:15 {Unbreakable:1}
    - IRON_HELMET 1 name:&eStarter_Helmet
    - IRON_CHESTPLATE 1 name:&eStarter_Chestplate
    - IRON_LEGGINGS 1 name:&eStarter_Leggings
    - IRON_BOOTS 1 name:&eStarter_Boots
```

@d3ath2005 I was quoting SupaHam. Have you tried it? Does it work?