Visiting visa Refusal

[vickylol]

Dear Members
My family friend uncle recently apply for visiting visa for United Kingdom from Pakistan has been refused due to several reasons.

One of the reason was that I was sponsoring my family friend uncle and I have submitted my documents which was tendency agreement and bank statement.
They say that your sponsor will help with this visit by paying for your trip and accommodation whilst your in UK and I am not satisfied that he is in a position to do so. The documents you have submitted do not demonstrate you have a genuine personal or professional relationship with your sponsor.

So, my question is that:

If my family friend reapply for visiting visa again so after how long he can reapply again?

What kind of supporting documents should I submitted this time for his sponsor which they raised question last time?

And how I can show genuine personal and professional relationship?

Many Thanks