"I am not looking for a word "
You keep demanding collusion; the three-figure amount of contacts prove the lies to America were no accident. As does the admission, by Republicans, it was a "grave security threat".
And 8 years later, we see we were correct all the time: Russia has infiltrated, and now controls, the Republicans.
Remember when both parties were hacked, but only the (D) emails were released???
Kompromat.
"based upon the cavalier attitude of those in the conversation on the insecure Signal app, was this the only conversation on this insecure app?"
Seeing as how EACH of the participants had a pro-active security responsibility they shirked, I'd have to say this was SOP.