Well, Warez releases comes with a moto, For educational and non commercial purposes!! So, they arent fit , or are not for a fully functional and public run!!
You wont need a warezhost to just check how it works! But, if you want to run it to power your sites, then you should have an offshore host!! I dont know why Dxseo mentioned you would need a warez host!
And about the risk, most of the scripts has callbacks in it, and eradicating them depends on the skill of the person who null it! So, if he leave a callback, the script's official team will come to you!!
Another thing is backdoors which will allow the Nuller to access your host! A nuller can put a backdoor, if he want to!
Atlast, not all people will mail you and beg to remove the unauthorized script from the server!!They will direclt forward the move to sue you, and hence they can warn all other people not to use their nulled versions!
~ExP~