Kfmi, I feel some empathy for you because I used to be a long time follower of Trinny and Susannah myself. I started to read their books even before they were on TV and my very first question on this forum here related to their body shapes. And I was taken by their body shape advice personally, because I looked through the book and saw one of the pictures and thought I could be looking in a mirror - they had got me. Looking back afterwards I don't actually resemble that body type exactly (it is not quite me on at least 2 of the descriptors) but it happened that I really like and resonated with their dressing suggestions.
I also feel a bit sorry for you because there is so much body shape information out there on the web, and heaps of sites just on the T & S body shapes and some of them seem to contradict each other.
But here's the thing. Right here on You Look Fab we have advice from Angie who is a fashion stylist and who dresses heaps of women AS HER JOB. And there is a community of women who are friendly, generous and polite who can really help you. You can post an outfit and they'll give you advice on how to improve that specific outfit. I'll take that advice over just reading a book, even if she doesn't use the exact body shape system you'd like. Although Angie uses just 5 shapes (and she compares hips and shoulders, not hips and bust) she also has many posts on what she calls modifiers
eg http://youlookfab.com/2011/05/.....full-bust/
http://youlookfab.com/2006/07/03/powerful-petites/. Sometimes those modifers are more important to how you dress than your body type. (in my case having short legs and a long torso is more significant than my body type) In your case it could being being petite sized and having a large bust.
Click here for more of her posts on body type http://youlookfab.com/category.....body-type/
Another person who has written a lot on body types and whose advice I respect is imogen Lampart at Inside Out Style. (It was actually she who wrote the post above on how to dress a full bust, as a guest blogger for Angie) She is also a stylist who dresses people all the time. She doesn't find the t & S system very useful and has her own system - with a few differences from Angie. She had a great series on real life body shapes and heaps of advice for dressing. You can also contact her - I did and sent her a photo and she confirmed what shape I was under her system. Here's a link to one of them http://www.insideoutstyleblog......pes-v.html (I am not saying that you are a v shape; you can link to the others from that page)
Both these people don't really deal with measurements but with how people look from the front, (You can see that in the picture on Imogen's page). I think that that is what Mimi and Arizaphale were doing too. I am sure they read what you wrote, it is just that they were looking at how you looked in your picture from the front. So a hourglass can still have a bust a couple of inches less than her hips because she'll still look balanced from the front (because some of the "hip" measurement is out the back in your bottom and not visible). Similarly, your ribcage measurement is of course less than the circumference of your your hips, but from the front it could look as if it is wider than the front of your hips.
I honestly don't think those body shape calculators where you just punch in the numbers are worth your time. There are other variables involved than ratios.
Now to your specific question "is the bust too big for the vase?" I'd say not. It certainly seem to indicate that someone's bust is on the larger size, but the I think the general idea was that a vase was balanced between the hips and the bust so it isn't a top heavy look.
You don't need to strip down to a bikini - form fitting clothing is fine - like leggings and a tight top. Just so long as we can see your whole body or at least your body from the neck downwards