Now on the broader picture in regards to Trump: I'm pretty sure that if enough digging happens, they're going to find any number of "ethically questionable" issues surrounding Trump. Those discoveries are already numerous, and there is no reason to expect there won't be more found. I'm sure even more digging may manage to turn up legal violations which are entirely in the realm of "technical violations" and subject to significant interpretation when it comes to his past business dealings. But that has little bearing on the Presidency itself.
In this case, it reeks of the Democrats doing to Trump what the Republicans did to the Clintons in the 1990's(Whitewater). If the Democrats really want to go down that road, that's their prerogative, but I doubt the outcome is going to be different for them today vs what the Republicans had 20 years ago.
What I'm really expecting to happen, as the Democrats seem poised to get their hands on most the material the Mueller investigation acquired, is for the "embarrassing leaks" to start happening as people get "outed" as having had business dealings with Trump in the past. The Democrats have made it quite clear in the past they have no mercy for ANY Trump associate. They're going to out these people, so that they can be properly scorned, much like the CA Proposition 8 backers being leaked during the Obama years.
I am going to enjoy the blowback that happens to the Democrats when their operatives get their chance to follow through on those plans.