I agree with you there Qhorin - it's just hard to type much covertly at work
I think if GRRM had not included any sex scenes the book would lose some of it's realism. As for the bloody mummers being fixated on rape - I don't see that rape as anything to do with sex. Rape is about power, humiliation, domination and control and very little to do with sex (that's just the means to the end).
Also the male dominated culture in which they live sees women as little more than possessions or prize dogs with no rights, sold off to whichever suitor has most to offer (alliance, wealth, political standing etc), rape was probably not seen as such a horrendous crime as it is in today's society. Women were just there to satisfy mens' needs and if it they weren't willing then so what? To common mercenaries like the mummers who live a brutal everyday existence (also hardly likely to rise high in their society) what better way to get their own back, and have what they feel they are entitled to, by taking with force that which they could never hope to get in normal circumstance, ie. raping some highborn, thoroughbred woman who wouldn't go near them in normal circumstances, or a lord's wife, daughter or pretty servant
I see it as an act of bitterness, they are the lowest of the low - looked down upon by everyone so they make themselves feel better by taking what they want from people weaker than themselves. No matter how bad or angry they feel they can always make some poor wench feel worse than they do and gain some measure of satisfaction and proof of their masculinity at the same time. It also adds to their brutal reputation and increases their infamy.