Papadop: duped / seduced by Italian (now wife), given 10k cash which he wisely left with European lawyers. Page: extorted using prior work for FBI helping them with anti-Russian counterintel. He clearly helped the USA but they probably flipped the script and accused him of being a double agent. Flynn, an anti-Trump maverick who was a known foreign policy freelancer. Probably extorted into infiltrating the Trump campaign. Manafort, a man with a theoretical 10-20 years of jail time but was never prosecuted (most similar tax cases are settled with fines). Possibly extorted into joining the Trump campaign.
Of course any or all of the four could have been Russian-connected but that is extremely doubtful. Any of the four could have been part of an election collusion scheme. However it is known that Halper and Mifsud have ties to western intelligence and that pretty much exonerates Papadop.
Page has a history with one of the very few successful takedowns of a russian agent. The Page collusion story was obviously being shopped. See http://thefederalist.com/2018/11/30/new-details-reinforce-fbi-used-fake-pretexts-start-investigating-trump/
Flynn is more of a mystery to me. Not sure what he was doing in 2016, but he was clearly part of a selective prosecution and hit job by McCabe in 2017. It's possible McCabe had earlier evidence from 2016 to go on, but it's much more likely that he just hated Trump and Flynn and wanted to take them out.
Manafort was the bad boy of the bunch but also hit with very selective prosecution for havng been part of the Trump campaign. "According to The Guardian, Manafort met with the WikiLeaks’ founder at the embassy three times—in 2013, 2015, and in spring 2016." see http://thefederalist.com/2018/11/29/guardians-manafort-story-far-just-another-evidence-less-spygate-smear-strategy/ Those stories seem to be post hoc narratives designed to justify the misuse of the intellgence services against a political opponent.
Even if you keep a very open mind about Russian collusion possibilities (which make no sense except perhaps as a general way to sow chaos), the misuse of the intelligence services is something fit for a banana republic. The deep state might well just be a bunch of over-eager McCabe types, but tossing the principles of justice over a botched political hit puts us way down on the slippery slope. Possibly without any way to recover without herculean political efforts, No republicans seem willing to step up and Dems are in the enemy camp.
depressing as the turnover of the House can be, the investigation information is all going to be turned over to the Senate for follow-up - hopefully, DJT has Barr in a twist...