You need to copy your account to the PTU again if you did it before you bought the Valkyrie, that way it will update onto your PTU account. It's been a common issue.
An lack of an SSD is the biggest handicap your system has. It's basically required to run the game, a HDD is not nearly fast enough. We can help you get it setup if you can double check that your motherboard supports it.
I would actually rather trade the Vulcan out for a crucible as the Kraken has refueling and repair facilities build in, there is an interior drydock hangar for repairs.
That is actually the exact intention. And if you have a prospector repairs and refueling can be done, I may also pay for the ore and resell it later on.