If you're counting holds I'd say that 7 SP is too many. Of course I dont generally carry more then 5 with or without holds.
You also have some good SPs. With that staff your could get away with punting holds, but that's giving away one cat a week. That's a loss each week. I'd go with 5 or 6 SPs, and add at least one RP that could get you some holds, with good K/9, era and whip.
Wagner and Valverde are good closers, but I'm not sold on Dempster at having any real value. If Shields, Linebrink, Ducherere, or Betancourt are available I'd snap them up and cut Dempster without blinking. You could try to move one of your SP, and Dempster to make room for a good MR.
How are your bats?