Hotel and activities suggestions for tourists (Johannesburg)

Hi everyone,

Johannesburg here we come! Can't wait till mid February when we'll be visiting Johannesburg for about 12 days. In desperate need of suggestions though, as what I find online has really overwhelmed me. I don't know what to choose. Has anyone got any not-to-be-missed suggestions on activities in and around the city?

Is it worth it to spend all 12 days there or should we split our time between Cape Town and Johannesburg?

A hotel, or even a hotel district suggestion would be more than welcomed. We err on the side of affordable rather than luxurious but safety first :)

Any local travel agency recommendations would be so much appreciated.

I know, I know, leaving everything for the very last minute doesn't make any sense for most of you but real life got in the way and now... run Lola, run.

Many thanks in advance and wish I can meet some of you while there. I've been speed reading posts for the last few days and I can say I am thoroughly impressed!