The fewer times video is "stepped on" the better so, I do want it to leave the original video alone if at all possible. Audio... don't really care. Most 44.1/128kbps stuff is good enough for me (partial hearing loss...) but, I am meticulous, so all my audio is at least 48kHz 24 bit AIFF for production. FCPX does quite well with AAC, but obviously it should be analyzed and fixed on import... it is not an editing format. *My* camcorder exports AVC/AAC audio. AAC is usually an MPEG-4 Audio format and pretty much the current standard for AVCHD video.
I have never seen SC Pro change the frame rate. However, I do know several consumer grade camcorders actually "lie" about their frame rates. Everything is shot at 59.94 and "interpolated" to the "advertised" optional framerates of 24 or 30 (technically: 23.98 / 29.97 p) if those options are selected by the camcorder user. If the video is 1080 -- it's 60i -- it doesn't matter what framerate you think you set (gotta read the fine print on these cameras!) 720 is actually 60p. SD is 60i interpolated down to (usually) 30i (and some cameras have the option of 30p.) So, Smart Converter must be seeing the original h.264/AVC video in it's native format when passing it through as 59.94 interlaced. That is not a bad thing. However, in FCPX, a 1080 project should be manually set up for 29.97p and have the 1080/60i media conformed to the 30p framerate.
PS - I've actually seen perceptible color changes/loss of dynamic range after using ClipWrap (it was trying to do a transcode...) so, not convinced. Quicktime 7 Pro is the best app to use IF it can open and play the original video. Every conceivable/available export option (depending on system installed codecs) is available, so ProRes + Apple Lossless (AIFF) audio conversion and considerably less trouble to use (and 20 bucks cheaper) than Compressor. Unfortunately, it is no longer included with the OS and part of the FCP toolbox [free "Pro" activation when installing FCP Studio — which is too bad]. The best scenario is having FCPX import/ingest the original video without the use of a extra or third party app. That is, however, not really an option for the OP.