I think the interactions seem fine tbh. Nothing majorly romantic and he just sees her like a copy of his dead friend.
Yes the fact that she is a copy of Kuina bothers him but this is also the fact that she wants to be considered a swordsman too, the fact that doesn't give up and want to fight, Tashigi dream to collect the best swords in world and to take great swords from pirates and people who don't deserve them etc.
Zoro in Ph ended up protecting her, carrying her through the labs. He also helped her a little during her fight with Monet.
It's all good and well to speculate this, but wouldn't Zoro find other women who he meets on his travels or in the crew more convenient to settle down with?
Obviously Zoro can find an other woman who can be a better match for him. But for now given te whole story we had I think Zoro x Tashigi is a serious ship. Kuina like, swordswoman, meet each other a lot during the whole story etc.
And I think the end of the story can help them to be together.
Why would he settle for someone who reminds him of Kunia 24/7. That means he hasn't gotten over her death, and makes his dream weird and less noble lol.
I think that if he sees Tashigi as his own person it would mean that he had gotten over Kuina's death. I think he already separates those two more post time skip.
About his dream I don't think it will lessen it : Zoro promised Kuina to be the strongest and he will be the strongest. His business with Tashigi after that his an other problem.
I can picture Zoro daughter to be also similar to tashigi but maybe with green hair and Zoro training her