The Big Band Mix and the World Mix sound good to me as well. When I have clipping I use a clipping repair preset that comes with Sound Forge Pro 9-11 and it works quite well. Also, Izotope Ozone 5 Pro does it automatically when you use it for mastering. There is a sequence I follow when mastering that is pretty typical for most mastering experts, not that I am one, but it does seem to work and it goes as follows: preparation of all tracks, noise reduction of all tracks, enhancements desired of all tracks, compression of all required tracks, clipping repair of all tracks, limiting of all tracks as required, and finally referencing the final mix to similar songs like your working on to see if they are comparable to other song in the same genre. Also, there is always a purpose for final mastering of a song to consider, and they are as follows: Final check, consistency, enhancements, album flow and finally formatting that you are looking for. These are the standards that I know about and consider myself, so I hope they are helpful for you and others as well. I think that as long as the final output is what your looking for (as a home studio and not as a professional) a finished product and sounds good to your ears, then you have done the best you can do. The next step would be to take it to the pros if your looking to sell your music. What you have do so far sounds just great. Nice stuff!!
Peace and Blessings, John