Scheduler functionning problems

Hi guys sorry to bother but i have a couple of problem ;
a) my customer has an event for 5 days where there will be conference, workshop and consultancy For the event with event manager it was exactly what my customer want now where i have the problem is that the consults are 20 or 40 minutes so i have to be able to show the time frame and let the customer choose the time he want and as soon paid the timeframe he chose should not be choosable again
b) some of the consultant will not be there the full day from 11AM to 7PM some only 2 - 3 days some afternoon etc..
here is the consultant page (sorry it is in french) each picture brings to a biography and this where i would like to have the booking available with time frame for this page all the consultant offer 20 or 40 minutes
on this page they offer only 40 minutes
c) on this page i added your schedule bit nothing happen
Hope you can help me
thks in advance