Absolutely none of this is evidence of his guilt, it's all just very loose circumstantial suggestion. If this is all it takes to convince people of someone's guilt in a huge criminal case, we're all doomed.
Circumstantial evidence has sometimes been enough for "beyond a reasonable doubt" in many cases over the past hundred years. I guess we were doomed since before then?
"Probable cause" is all you need for a warrant. With the warrant you secure the "beyond any reasonable doubt" evidence.
No, the financial transactions will prove his guilt. This is for finding him in the first place and getting the necessary warrants. Also, note that this evidence is for the indictment, which is what it takes to bring the charge, not a full statement of the case at trial.