In short,
Yes.
Best two years of my life, and taught me a hell of a lot.
It is safe there, the only risks are the ones that you take yourself. In other words, it is as safe as you make it.
Before you go renouncing your English citizenship, contact your closest Botswana consulate or Botswana Immigration, and see if your ex-citizenship will allow your to get a resident's visa. Once you have the visa and work permit, then there is no need to renounce your British citizenship.
Get it done ASAP though, as you said, the red tape is only getting thicker.