1) Well, Polyphonic Legato is only a feature you have in the Instruments Pro Player. The normal Instruments Player (so the one you don't have to pay for) does not support Polyphonic Legato.
Therefore the free player "always" interpret 2 notes as a legato transition (so in your case it would sound like a Acciacatura).
If you use the Instruments Pro Player you could check if the "Polyphonic Legato" Option "Advanced Mode" -> "Options Tab" -> "Interval Mode" is set to Polyphonic and "Advanced Mode" -> "Advanced Tab" -> "Interval Mode" and "Interval Threshold" are correctly configured.
2) Well, there are tricks like using a lower ensemble size (or solo instruments) and then transposing them and pitching them back and giving them 2 independant staves, but the only one where you get a more believable divisi sound is by using the Dimension Instruments (so Dimension Strings or Dimension Brass) as both are recorded in a way that you have seperate musicians. And with the help of the Instruments Pro Player you can even let them divisi themselve when you play more than one note (so you can on the Dimension Violins for instance even start with 8 notes at once and after that all play together and it would work, but it use a lot of ressources).
I hope that this helps you a bit