My objective answers in red.
The fact he got elected President in the first place gave you an "impeachable" offense. Please don't even act like you have ever suggested otherwise.
I'll deal with a few.
On # 1, I agree, has to be reasonably reliable proof he knew, such as testimony either from himself or from one of the meeting participants. That could largely be what the Grand Jury is about. Will Manafort, for example, say he told Trump they were meeting with an attorney from the Russian government with dirt on Clinton.
You have to admit, his comments that week certainly give the impression he had reason to think they were about to get some info on her. Right now, the only thing we know that would be the source of that is this meeting.
On # 4, I am assuming that is as payback for something they did for him. The evidence of it being direct quid pro quo I admit my threshold for that is certainly lower than yours. But knowing how Trump loves to brag, I do think it likely he would have made comments or left a paper trial about how brilliant a deal he struck.
On # 5, you want me to define significant, but remember Trump has already gone on record adamantly denying ANY involvement with them except for the Miss Universe pageant. So no, I'm not talking about them having some tiny interest in a bank that gave him a small loan. But if he is tied financially to Russians, or a one cut-out go between for millions to sustain a deal or buy a building, I would hope you consider that significant.
On # 8, okay, you made your point that the intelligence services are not fans of his. But remember, their mission is to detect exactly this sort of thing. Whether you think it is ultimately innocent is irrelevant. The fact that it occurred, under circumstances evincing a desire to evade scrutiny from obvious places, is highly suspicious. And we still have very little information on it.
Bottom line is that the WH says it is eager to cooperate so as to bring this to a conclusion. That seems at odds with Trump's comments that Mueller cannot go into Trump's finances. I suspect that the tension between those two statements is going to come to a head in the next 30 to 60 days.
We'll then see how eager he is to cooperate. I'm going to go out on a limb and say "not very."