The level of advice you get is directly based on the level of information you supply.
IB is not career switching friendly anymore, very difficult to succesfully make a big transition into it these days. HBS is going to be next to impossible...they are trending very young and your background doesnt fit into the mold of what the old folks they accept (military, Drs, lawyers, etc). I will say the same will apply to Stanford. Your energy is probably better put applying to some schools where you will be more competitive. If you want finance take a look at Darden, NYU, and Cornell. Go for Chicago, Columbia, and Wharton in R1 but the be prepared with a list of other schools that will be easier to get into for R2.
Kellogg Class of 2010...still active and willing to help. However, I do not do profile reviews, don't offer predictions on chances and am far to busy to review essays, so save the energy of writing me a PM seeking help for these. If I don't respond to a PM that is not one of the previously mentioned trash can destined messages, please don't take it personally I get so many messages I have a hard to responding to most. The more interesting, compelling, or humorous you message the more likely I am to respond.