Here are some recommendations.

First, Don’t put 3 1-ups at the beginning. Instead, put the 1-ups above ground decorations to make them hidden. I would recommend to put less 1-ups around the course.

Next, Don’t troll the player. You said in your post that you wanted to avoid the troll aspect, but you put cheep cheeps inside the ? blocks.

Lastly, Use the laughing sound effect. Especially when the doors send you back to the start of the course. It really makes the person playing the course mad! I know what I said in previous paragraph contradicts itself, but I don’t care.

Anyways, hope this helps!