rMBP and external SSD ?'s

so I just bought a 256gb Samsung 830 SSD and (until a thunderbolt enclosure comes out) an INEO usb3.0 to SATAII enclosure.

so here is exactly what i'm going to do:

the primary reason is to offload iTunes library from the precious space of the rMBP 256gb HDD and use the external for entertainment.

what I would like to do is:

1. install and run Diablo III from the external

2. install and run steam, Counterstrike: Global Offensive and other games.

2. partition 30gb and boot from windows 8 (not sure if this is possible with the current version of bootcamp)

so I understand with windows you can install to an external, but lingering data is installed on the primary C: drive and i'm hoping this is not the same with ML. I don't want any lingering data installed on the internal SSD.