I am interested in what will actually happen as a result. Impeachment? Would that even be enough? Rex Tillerson would have to go too, at the very least. Or will absolutely nothing be done?
That's the first question I ask when people start discussing it.
IF investigators start researching it, and they discover whatever it is you suspect you would find, then WHAT SPECIFICALLY would you want to have the law do?
I don't think there's any doubt that Russia had some involvement in elections, nearly every nation does. Just like the US has some degree of involvement in other nation's elections.
A much harder question is what degree of involvement there was, and if that involvement could have modified results in a significant way. Note that polling and both of the polls and vote-by-mail ballots showed Trump winning the various districts (few were closely contested), and the state results were unlikely to be materially swayed. Even then, more than one state would have needed to be swayed to adjust the results of the electoral college. Some reports said that if three specific near-tie states had their results dramatically tied it would have been enough to sway the election, but you're looking at several hundred thousand votes spread across many polling districts, each would need to be subtle enough to escape suspicion.
But let's say that happened. Somehow the election was subverted so much that the vote swung in those states, hundreds of thousands of votes across multiple states that survived recounts in many districts, and it would have been Hillary instead of Trump. And let's say it was Russia behind the hypothetical situation.
What then?
Would you have Trump impeached? The Constitution only allows for three reasons of impeachment; Treason (defined as giving material aid and comfort to enemies we are at war with), Bribery, and Maladministration (called "High Crimes and Misdemeanors" in that era, but understood to be the term of the era for maladministration). Since he wasn't in office at the time, neither Bribery nor Maladministration could apply.
Would you have the nation declare war against Russia? That's a frightening prospect.
Would you have the nation take it to the UN or some other international body? Remember that for most bodies both the US and Russia have veto votes, so either nation could shut it down before it even starts.
Perhaps you'd look for trade sanctions? Those would be tough to justify without a diplomatic goal, especially since (in the hypothetical findings) it would be government administrators and covert actions that would need to be addressed.
Maybe the request is to have Trump voluntarily step down and Hillary take up the role? There's no constitutional provision for that.
The results of inquiries may be nice to look at, good things to know, and may reveal weaknesses that should be addressed. I'd go for that, finding ways to better secure the election like removing electronic machines and going to simple pen and paper votes, hand counted by multiple people and reported and certified by those same people.
But apart from that, what would you expect would happen?