They could not say you should take a TAXI
for the first question:
I asked the same question to them, no one took this dare. and no one told us we should not call the ambulance, they just told you this is the doctor's words! But when the thing happened, where was the doctor!
for the second:
I think you should not take this risk to call a taxi instead of ambulance, since if you are in a REAL emergency case, you do need some special care under the way to the hospital.
I was in CHEO emergency room with my friend's kid long time ago, also a very bad experience. Maybe the only thing you can do is: pray not to go to any hospital.