Air Carrier inbound to CLT during simultaneous approaches was not issued an intercept and flew through the localizer; resulting in multiple TCAS RA alerts. Separation was legal; but a go-around was initiated by parallel traffic.

Narrative

We were given a course by CLT Approach Control of 150 degrees toward the localizer for [Runway] 18R at 3;000 FT; but never told to intercept. Air Carrier Y was on approach to 18C at 4;000 FT and the two aircraft began to cross paths and get RA's that were reported to ATC. We were then given a right turn back toward the 18R localizer; again under flying Air Carrier Y and getting a second RA. The Controller mentioned several times that we were separated by 1;000 FT altitude and not in danger; but Air Carrier Y elected to go around when he could not see us during our turn beneath him. We had a visual on Air Carrier Y the whole time and closely monitored our closure to him and were not in danger of collision while awaiting a course from Approach. As mentioned; we got two separate RA's and it sounded like Air Carrier Y got two also from what we heard on the radio. There were two aspects to this event. The Controller never gave us a course to join the localizer and our course led us to converge on the 18C approach path. [Also]; the Controller did not realize that the two aircraft were getting multiple RA's; although he separated us by 1;000 FT.