Nice guide, helped me a lot. Although I'll try and help some with the same problem I had tonight.
The thing is, I had done everything in the guide (bike and kart races, carnival rides, etc.) and had 331 clothes but 38 errands completed. It seems as though the game had glitched and did not send me any errands to do. I had the game completed at 99.76%.
I went to dashboard and loaded the game and completed 2 errands, to my surprise, it got me from 99.76 to 99.83 only. Luckily i remembered that although I had 331 clothing i still had 2 things to buy from the Final Cut shop. I went there and bought the 2 parts of clothing left.
This unlocked a KING outfit (Im spanish, in my game says King in spanish so I suppose thats the name) and got me to the 100% and the achievement. So I recommend BUYING EVERYTHING from the shops, just in case.