I wrestled with the thought of actually writing this. A part of me is always looking at things through a slightly off window and I am constantly thinking of what could have been done despite what is. That said, I really do not believe in theming an entire land around a specific movie, and I feel my decision to write this may be misinterpreted as support of WDI's choice.
So... where to begin
It's been a while since I watched Bug's Life but there are specific things that were done, and several things that were not, that prompted this thread. I love Flick's Flyers, but I am not a huge fan of the real estate taken by all the water distractions. My first thought would be to combine both sections of the water area into one. It would be fairly simple to combine a leaky hose with a giant fallen nozzle that could easily drench people.
My next headache is Heimlich. I am not sure what is more annoying, the fact that you are inside of Heimlich, the fact that he is gorging himself, or the fact that there is NO POINT to the entire trip. Solving the first problem would be simple... Make Heimlich a solid caterpillar, add multiple saddles to his back, and then allow for left/right/up/down movement as he lurches forward like a normal caterpillar. Aside from that I have no clue how to draw a more immersive story, or how to ditch all the food.
I am a HUGE bumper car fan, but I really really do not like the whole Tuck n Roll setup. For starters it takes up a LOT of the real estate in Flick's. Then there is the added insult of not having the Bumpers in Paradise Pier where they belong. Personally I would advocate it's removal in favor of a much better attraction. I am not sure what it would be called, but think of it like the current ant farms. It would be interesting, multi storied, and on the top level you would have a section with a giant eye starring at you... what better tribute to ATIS then this... just a thought. It could easily be themed around the giant beetle since nothing else is.
While I do not remember their names, both the spider and the stick bug are completely unused. How about a complete walk around the entire area, similar to the Ewok Village or Fort Wilderness. Nothing special, couple bridges etc, just something for the kids to climb on. It would have to be out of the way of Flick's... but they could allow a tunnel into the new "Bug House" that would allow you to see the ride and the ride to see you.
Now to the Ladybug business... again not a big fan of being IN a bug. So... acorns... they are round, shaped like a top, and can be spun in a similar fashion. If I remember correctly the grasshoppers were after these nuts... so that would allow you to incorporate them into the land as well, possibly one opening the bottle as in the movie.
All of this was written to make a specific point. Some individuals automatically link theme with attraction quality. I feel that Bugsland has an amazing theme, regardless of how misguided I feel it may be. However, theme is only part of the picture, I feel something similar to what I have proposed would possibly complete it.