I'm not familiar with Genesys as a WFM application, but I am familiar with its functions for call routing and CTI. I am guessing you also use those modules?
If you purchased Genesys a long time ago, it may be worth looking at the market again for new solutions. I think usability is a key factor in any technology. Call centers have turnover, it's the nature of this business. Attrition leads to new people in new positions, both through promotions and through new hires. If your training requirement for your technologies is that extensive, the technology may be cost-prohibitive in the long run.
The usage scenarios you describe are complex due to the diverse skills and low volumes, but not outside the capacity of good WFM software. The hardest part for your staffing is going to be managing the low volume clients, because a single missed call or long queue time can have a greater impact on your stats. Do your service level agreements have a stipulation that they are tied to a forecast?
rick.daley@invisionwfm.com