Earlier quoted context omitted.
Is the supposed evidence of Russian interference at all dependent on these false FBI claims?
No, all 17 intelligence agencies confirmed Russia meddled in the 2016 election. The Republican minority report from the House intelligence committee also agrees Russia meddled in the 2016 election.
No. : "New York Times Forced To Retract Longstanding '17 Intel Agencies' Lie About Russian Hacking":
https://www.zerohedge.com/news/2017-06-30/new-york-times-for...
Ann Coulter addresses details and history of the "17 intelligence agencies" claims in her book "Resistance Is Futile!: How the Trump-Hating Left Lost Its Collective Mind":
https://www.amazon.com/Resistance-Futile-Trump-Hating-Left-C...
The sole sources of the claims were found to be only John Brennan and James Clapper.