I think it is not possible for someone to make 30 or 50 posts in an hour. A better example of post bursting should be around 10-15 posts per hour which is also going to be a hard thing for many users. I believe that Icopress warns those users who just want to complete their 25 posts limit as soon as possible and some users may post more than 10 to 15 posts per hour in order to complete their weekly minimum posts for a campaign.
It is possible for a person to make 100 posts per hour (if there are no limits, never tried, so don't know if there is any limit in per hour) but you said it is hard to make 10 posts in 1 hour, and you are 100% right, because I made around 10 posts daily, from some time, and I know how hard it is to make 10 posts in only one hour, but if you are active in the local board then you might make it happen but there you can not post consecutively, thus it becomes hard. But if one makes up his mind to make 10 posts in 1 hour then he can easily make it.
And you are right about completing the limit, if one is found doing that, then he or she will be given a comment on the spreadsheet and that will be a warning as well. If that person does not stop doing that then will be removed quickly for not following the rules.