True. Maduro has not been the president since the last elections; he merely usurped the position. You cannot perform such an action without facing some constraints. For him, personally, maybe this was the better outcome.

First, read up on Venezuela's oil. I don't think that's the case. At the very least it's very expensive oil, hard to use and very bad for engines, refineries and for the environment and also oil is over (meaning oil will go into terminal decline probably before 2028 and that will be the end of the oil companies)

Second, when the US did have Venezuela's oil things were going a lot better in Venezuela for the whole population. So would that really be such a bad thing?

Third, Chavez made things so bad in Venezuela it's tough to imagine this making it worse. Oh and then he died and Maduro came ... and made things worse.