I think you know as well as I do that you have a VERY GOOD shot at all the schools you’ve mentioned including Harvard, which is only a slight stretch. Wharton is a reach and is about as selective as Columbia. You haven’t mentioned whether you’re a guy or girl. If you’re a girl then I would say that Harvard is a reach for you and Stanford is the only stretch.
To answer some of your questions, I don’t think that it will make any difference to your candidacy whether you apply with 2 or 3 years. In general, all schools are younger applicant friendly but given the current economic environment, you might be better off with 3 years experience. You will want to see how the economy is shaping up because you will have a hard time getting an H1-B, especially in the consumer/retail goods sector.
Also, this extra year might give you a chance to work for a client in the field you are interested in. You definitely need to show a strategic understanding of the industry you wish to work in. You also need to think about the career path you wish to embark on post MBA and more importantly, how your career could shape up from there. HBS doesn’t care much about your detailed career plans but all of the other schools do. You need to think about this regardless.
Your year at the nursing home adds a nice human touch to your profile. I’d say that you come off as a well- rounded candidate. This is what b-schools look for above all.
You’ve done a good job short-listing your schools. I think Columbia and Kellogg would probably prepare you for your new career better than the other schools but HBS and Wharton will help you land a better job
. Plus the brand/network is stronger and carries more weight if you decide to return to Europe. Tuck and NYU are good backup options as well. If I were you, I would cut out Yale and apply to Stanford as a stretch school. You definitely have a shot.
Anyway, good luck with your applications. Don’t get over confident though because you still need decent essays to get into these schools. But still, the spot is for you to loose. I would recommend waiting for a year though. You definitely want to see how the economy is shaping up because you will need a good summer internship to make your transition and that might be hard if the economy gets a lot worse, especially because you are not a US citizen/permanent resident.