So I quickly checked on Internet and here's how it should be imo :
1. As most of steam games it's economy relies on skins, so I remembered a nice plugin which could be used
https://gamebanana.com/gamefiles/3560
Skins could be received by opening cases which you could get by killing enemies, collecting presents from ground, etc.
There should be a database saving skins and equiped skins (preferably MySQL)
2. Free For All mode (everyone fights for themselves)
3. Random spawns
4. Since PubG maps are way bigger than Cs 1.6, I would suggest to use FOG to limit vision of players thus making it harder to find each other.
5. Some kind of a rating system (kills, survives, deaths, etc.)
Correct me if I am wrong or add if I am missing something important (never played PubG)