A few things to consider when going boomless :

the length of the foot of the sail has to be shorter than the distance between the front & rear beams. This is because when you sheet in the main, the foot must be pulled out toward the rear beam as well as downward, if the foot is longer than this the foot will remain full & the leech will hook.
You will still need some form of mast rotation control / limit. Have a look at the Dart 18 for inspiration - they have a line which runs through the eyelet in the clew, a predetermined length, a little longer than the foot of the sail. Attached to this is a snapshackle which hooks onto your mast rotation limit arm, and hangs below the foot of the sail when not pulled tight. When you sheet in the mainsail your mast will rotate until this line becomes tensioned, this prevents your mast from over-rotating.
Personally I believe it`s better to keep the boom, what else can you hit the crew over the head with when they don`t listen ?

Hope this helps
Cheers
Steve