For those of you have a beautiful fully planted goldfish tank, did you ever had problem with goldfish chocking with gravel rocks? If so, how would you prevent that to happen again? Also, I've heard Goldies like to move around rocks, so how would you manage between the goldies and live plants?

I haven't had problems with gravel being in my goldfish tank. I used to have larger sized gravel but now I have medium gravel. I just keep extra gravel in the tank so if the goldfish move the gravel I do not have to worry about the plants coming out.

I have had serious problems with goldfish choking on gravel, a few members have even had goldies die after swallowing it
The best thing you can do is have large river rocks, the fish can't get them in their mouths. Also, this makes keeping the tank clean MUCH easier. I went with this route, and put my plants in containers, here's a pic

Thats how I do my plants. I had a heavy planted tank once, and it was a bad idea with them. I had Java Moss that grew into the gravel and then it was kinda like a thread and got into one of my Oranda's wens.....So I took the gravel out and moved the moss so there wasnt so much....

Now my tank has just Anubis in there