After having determined this information was too important from a NatSec perspective to be cast to the whims of politics, he went to the Authorities, not to Clinton's campaign.

One somewhat legit 'strike against him' however is the fact that when the FBI seemed to be sitting on it, he started talking to reporters about what he'd found out. That action has given the wingnuts a talking point to try to paint his actions as having been driven by politics/him being in the bag for Clinton. It's BULLSHIT of course, but that's a RWNJ talking point, trust me.

Sure, he's a Brit, but they haven't qualified as our adversaries for a couple of centuries.

His brief was to look into any Russian skeletons in Trump's closet. The research company likely had others preparing other info, i.e. NY issues, Middle East issues, etc. for the candidate, his companies, and his family.

Steele was dealing with information

Putin was trafficking in stolen goods.

the difference between doing your own internet research and clicking a promising link in an unsolicited spam email.

They both might yield the information you're looking for, but one carries a much higher implicit security risk so everyone with half a brain knows not to do that and to instead alert your IT/fraud department to make them aware it's happening.