I wrote three sets of letters before getting a singular apple which was my only piece of foreign fruit. I planted it and two days later I come back and there's a house built directly on top of the spot I planted it on. Unbelievable and I went in to say hi and he was rude too

Oh my gosh, that happened to me in AC:WW! My only Peach...

If you don't want villagers to crush your trees/flowers plant them far away from signposts. Those are the only places where villagers can move in in ACGC, WW, and CF. And Gaston if I remember correctly is a cranky so if he isn't being rude to you at first that would be strange. They're worth befriending though!

Yes, exactly as Bill said. Planting fruit trees near signposts is dangerous. In fact, I'm not sure it would have grown anyway.

Sorry Gaston done did you wrong, though! But don't worry, I'm sure he didn't mean to!

As the others said, don't plant fruit next to signposts, as they are villager houses.
However, I'd recommend placing them one square away from your own house, because no one could move there.