She would have been with Logan because they belong together... they are epic...
She is more like herself when she is with Logan than she was with Duncan or Piz

Nope, I don't think so. Saying Duncan had never left means Meg had never had the baby, means that Duncan and Meg never got together at all, or etc etc. Anyhow I think Veronica and Duncan would have stayed together.

Veronica loved Duncan so much that I don't think she would have been willing to hurt him by entering into a relatiosnhip with Piz or Logam.

She would have gotten back with Logan eventually I believe!

Also remember when she dreamed of her graduation?? Lilly and Duncan were both there but she was with Logan, meaning even if Lilly hadnt died and Duncan never left they would still be together!

She was with Logan before Duncan left, so yes, she would have been with him again, because he was the one she really cared about, the one she hoped was behind the door.

Veronica and Logan were together before Duncan left, I'm sure they would've gotten together eventually once again.

Yes. She was with Logan before Duncan left anyways. Duncan and Veronica were never meant to be, they would have eventually broken up even if he didn't leave. And, as someone else mentioned, she wanted it to be him at her door.

She was with Logan before Duncan left so yeah I think.