At this point I don't see how anything can be ruled out. We don't know what those testifying behind closed doors are saying or will say. We don't know if those in the IC that have access to conversations between the Russians and Trump people have even testified yet. We're only hearing maybe the one fourth to one half of it that is public.
Agree - nothing can be ruled out.
That said, plenty of what's been said under oath does not support the collusion story.
Virtually all of what "supports" the collusion story is from un-named source leaks to the media. Sworn testimony points the opposite direction.
Did Russia attempt to interfere in the election? Yes. Repeated testimony says full confidence in this conclusion.
Did Russia prefer Trump to Clinton? Qualified yes. Testimony indicates that is the opinion reached but not as confident as attempt to interfere.
Did Russia infiltrate voting process? No. Testimony says no evidence.
Did Russian attempted interference impact the election results? Testimony says they cannot assess and are not assessing (other than attempt to see if actual votes were changed).
Did Trump's campaign work directly with Russia in some way? Testimony so far has said no evidence.
Are Trump associates under investigation? Yes - one for sure, Flynn who apparently lied about connections to Russia. Speculated that others Manafort, Page, Stone are all of whom had prior relationships with Russia. No evidence presented (or assertion or suggestion) in testimony to suggest Russian relationship was collusion on campaign.
A story has been floated supported by Dems that the answer to all of the above is YES. An important question would be do Dems have a motive for floated this version of events? We all know the answer.
My point? What we know so far points away from collusion. That doesn't preclude it but as we all know this thread began as a conclusion it occurred. Seems the skeptic would want more than the thin gruel provided so far before buying the story promoted by Trump's political opponents.