Only the first point is relevant. AFAIK the whole tablet project was opportunistic - plans weren't long-standing, they just jumped on it when they realised tablet hardware in general was quite cheap and Intel were offering even small players some sweet, sweet subsidies.

Re: Documentation, the devs at Jolla only appeared to find out or realise that it uses UEFI BIOS some time after the deal had been done and after the launch ... whilst I'd put that down to naiveté, they hinted in the blog post that they were having some difficulty discovering or finding documentation for how a lot of stuff works. I seriously doubt if Mediatek's rampant success of late is in spite of poor documentation for partners (for general public is another).