I think you should be able to buy all of the scratchers at the same time. Keep in the bot detecter. You should break it down to levels, just like you have it now.
There aren't alot of players that are gonna it there for hours and scratch. Lets be able to buy them in bunches/ or lots. When this is bought , the player will still have to sit throught the bot process and click the O per 25 tickets, that will take less time and will have the same chip outcome "per buyin".
The only thing that will change is the time of bought and scratched. The levels of some people will keep them scratchin all day, how the hell is that workin. I think if you can let them buy in "Lots due to level" and "scratch at once"you can still make a profit. Even if someone hits the lottery you still have the post profit from purchase in the same lottery