Dear all
thank you so much for all the replies, that's very helpful. I forgot some key info, of course. I'm planning to start on "Hard" difficulty because despite my problem getting a grip on PoE I have played most every notable RPG since ..uh.. many years. (Except Skyrim, and just because I hated the inventory screen). If I can't do hard I know I'm doing something fundamentally wrong and I rather restart after 2 hours than 2 weeks.
I realise that a lot of info is outdated with patch 2.0 (haven't been able to figure out if there were massive changes in 3.0, I guess not that much) but even the info past 2.0 is sometimes somewhat.. contradictory :D For example I still don't know if INT for a ranged rogue is important, meh or negligible.
But @rheingold raised a good point. During my first run I'd definitely like to have the reasonable maximum on dialog potential.