This is a complicated bot to make work regardless of who wrote it. You need to take precautions such as entering the farm before you press start, to make sure: A) no one else is already in there farming, and B) keeping an eye out for people that don't follow the first precaution because they will come in and start planting in your rows.
I always grab seeds, enter farm, set world, and start the bot while standing exactly where it plants the first seed. If you do this and keep an eye out for crashers/idiots, this bot will work flawlessly.
As for the 96/100 comment I feel like it would be a waste of time to just do 4 plants in the same time it takes to do 16 or 20 you know? If you've got a stable enough connection (<= 50ms ping) to the worlds you should be able to do 5 lanes.
Again, thanks for the feedback!