hello,
it is true that the access to Cream lake has no trail, and might goes below the tree line, but then that's part of the fun! It is a "historical" part of the Bailey range, and very typical of the Olympics. So I would not declare it unpleasant at all.
apart from that, about the traverse of Olympus connected to the Bailey range, there is a weight issue for the technical gear: you absolutly need it: (ice axe, crampoon, rope, harness, rescue gear for glacier travel), but it will depends on how much you can carry. If you think you'll have a too heavy backpack, then goes for light equipment: you can save a lot of weight with light ice axe (air tech racing grivel), crampoon (camp XLC470), rope(light 50m 8.1mm rope for two, a 30m could go maybe), harness (XLH130 camp), and the usual backpacking light stuff. But usual equipment works also, it really depends on one capacity to carry a big backpack...