Every team doesn't get guaranteed money for their draft picks. That's part of the reported issue with Rusell, he wants a six year contract and the Raiders don't have the cap room for 6 years. Releasing Moss doesn't automatically free up cap room, at least not all of it, teams still have to eat up the dead cap space, which is called "dead money". Randy had 11 mill left on his contract, I don't know how that ends up breaking down but that's a lot of dead money over the next two years one way or another.
The Raiders did allocate $12 mill for their rookie pool but long-term contract is a different story.
Also, Rusell doesn't have to play with the Raiders. If he doesn't want to play one way or another a trade could materialize. Same thing that happened with Eli Manning with the Chargers on the trade with the Vagiants.
It's a bad management by the Raider FO.They should have just traded the pick. I don't know how it goes to a few years back but as for the last couple of years, #1 pick contracts were pretty much locked up before the draft.
People could like the Raiders all they want because they like the colors and whatever other non-football related reason but it's a dysfunctional organization not worth the time with the current management.