Considering that Wagner straight up betrayed Russia and started a march on Moscow that might have succeeded if they weren't paid off then i wouldn't be too confident in their ability to do anything other than immediately surrender once they get a better offer.
After the "accident," the Russians had Prigozhin, the old leader of Wagner, suffer. Wagner was then folded into the Russian military complex to serve in more of a "Russia is TOTALLY NOT INVOLVED IN THIS" operations, especially in Africa. So I don't believe they would "betray" Moscow or Maduro. The Wagner of today is under Putin's control; however, that's not to say they couldn't have been bought, or that this might be some gift from Putin to Trump.
Likely, they were killed because Wagner has proven again and again to be a lot of hype with no action.
Reinvestment in the country now that the retarded communist is out will return the place to a 1st world nation in less then ten years. You forget the wealth oil brings when its managed correctly and people are paid properly for their work.
And of course, that stability brings back the tourism industry. The place was and still is, a beautiful destination for travelers.
Venezuela has a lot of resources, but the simple fact is that US/Chinese/EU companies will move in and start to extract. The only way that will not happen is if the government there is solid and working for the people. I am not talking about some commie shit, but where domestic manufacturing is prioritized. Still, there is a focus on using the taxation of the resource extraction to fund public works and industrial manufacturing.
You think the US would be okay with whatever new government comes into Venezuela being protectionistic, because a pure open "do what ever" will not work. You also need a restoration of the government not to be corrupt. So you need a complete re-establishment of civil services in most cases, or else in a few years you will see the same shit again.
This all costs MONEY!!!! Who is going to pay for it at the start? I guess the US will pay to get the country back on its feet, or else it will be back to square one. Then there are the gangs, they have to find some way to deal with, and that will cost more US tax money.