Just a few questions...
1 - How old are you
2 - What qualifications do you currently hold
3 - Are you prepared to study for more qualifications?
Obviously I don;t know you but from the careers you have in mind, these are my thoughts.
Mortgage Advisor - not the best time to think about becoming one of these! Also, I would imagine that most MA's have access to databases of 'best deals' etc and don't actually have to search very hard.
Medical Secretary - surely this is just a Secretary in a hopsital? I don't see how this would be helping people and giving customer service, I would think it was just like a regular secretary (taking minutes, typing letters, notes etc) only you would need knowledge of medical terminology and language.
Nurse - couldn't do it myself (all that blood...) but it is a worthwhile profession and definately helps people so if you fancy this, go for it!
Phlebotomist - I have no idea what this even is!!!