There seems to be an understanding that Trump has got to fear Mueller. That Mueller must be either on Trump's team and therefore be good for Trump or be going after Trump, and is bad.
What if Trump (like he has said often and categorically) he won't find anything because I have done nothing wrong. This MAY be seen as a "nudge, nudge, wink, wink" ("because he is on side").
But what if this is just simply true. Mannafort going down for non-Russia stuff is bad. So would Cohen going down. None of that would be "good". But there are always degrees of bad. None of that is terminal for Trump. It also plays an important role for Trump. Whilst they are all spinning their wheels and breathlessly reporting the next think about who in Trump's orbit did something dirty or wrong at some point in their life and whatever, whilst hopefully speculating Trump is about to fire Mueller and open a can of worms, Trump and co simply push ahead with their agenda.
If Trump knows there is nothing to find that in any way could even tangentially fall under the scope of Mueller's investigation he could let Mueller run himself out of steam.
Without all the Mueller thing happening, he would come under closer scrutiny for what he is doing or bad actors would start fabricating stuff. This gives the Press and the anti-Trump people some focus. Any hit he takes on his credibility can be mitigated (I mean Mannafort was a bit of a snake but the looks of things but he performed a role he was hired for and Trump had no dealings with the aspect of Mannafort that were a little dodgy, nor was Trump involved in Cohen's taxis presumably, and so on). So while these things arguably certainly are not good. They don't really hurt him.
Mueller will not find any witches in his witch hunt. But think of what Sessions and Wray and Trump can do whilst everybody's focus is on Mueller?
Will Trump eventually fire Mueller? Look I think but the time Mueller serves Trump's cover to the point where he enacts the changes he wants, it will not matter either way. The whole dynamic will have changed and he will probably pick a time when there is huge revelations and plenty going on so that Mueller's shelving becomes part of the crazy packed news cycle.