well for the first, no. because a med student would take a decade at least to see real money coming in. in most cases they see wealth at the age of 40 or if your really really good as young as 35. even after becoming doctors, they still have to get money from their parents for specialization, tools of the trade, etc. BUT they do not have an age limit. so for some they tend to go GP first to get money then specialize if they think they need it.
it depends, if your passion does not include specialize studies in BS math, medical, law, etc then yes. but in your case, i think its a specialize course but i dont know anything about eng so i really cant say.
as they say aim for the stars so if you fall, you'll end up at the moon.
maybe our resident engineers can answer your question better.