Well lets just pick one thing for now as I need to get to bed.
Trump Jr. was soliciting information of value in full knowledge that it was from a foreign source. I know that one of the guys will butwhatabout Steele, that is a different matter.
https://www.law.cornell.edu/cfr/text/11/110.20#
"(b)Contributions and donations by foreign nationals in connection with elections. A foreign national shall not, directly or indirectly, make a contribution or a donation of money or other thing of value, or expressly or impliedly promise to make a contribution or a donation, in connection with any Federal, State, or local election."
As political dirt is expensive to search for usually, it can be safely considered "other thing of value".
Actually, googling the definition of solicit in this case I found this article which explains it better than I can.
https://www.vox.com/world/2017/7/10/15950590/donald-trump-jr-new-york-times-illegal
Yep,and there is indisputable proof of this.