It's obvious by this thread that us people in the US are just a different society when it comes to vehicles than the Euros. I laughed out loud when I read "a huge 1.6 Fiesta" As far as I'm concerned something with an engine that size is a child's go-kart. I have friends and family that live out on their ranches and as children they had vehicles like that, and in many cases full sized ranch trucks they were driving as young 10 years old.
My first car (which was given to me) was my mustang- it was my Mom's first car in high school, she drove it through college then put in her parents garage for 10 or so years before it was driven up here 1000 miles away and parked in front of our house for another 5 years or so (well, not exactly, I have really fond memories of her picking me up from elementary school a few times in it before it was parked) before I got my license and we got running again for me. 5 liter engine, fairly poor handling at higher speeds but easily good enough to be a daily driver. My second, and payed for, car is my Grand Prix. Supercharged 3.8 liter engine, blows the Mustang out of the water in every aspect except style. Insurance for my cars is a little higher than most people would like for their cars at my age, but why the hell not I say.
From day one I've always treated these cars as weapons and I never went head on into driving them without fully learning how they act, and now when I do have a little fun in them I make sure it's in a completely safe area. Not every new driver is an idiot, just take it slowly and learn properly and you can start in whatever car you want. You do not (and should not) need to use any more than 1/2 throttle for any around town driving, regardless of the car. I understand if you've got more power available it's very tempting to use it, but be smart and know when and when not to.
Everyone here who says a new driver should only be limited to some tiny little piddly weed whacker powered car needs to lighten up. There are people capable of not being a complete moron. Get whatever car you fancy as your first car, all you have to do is respect it and be smart about it and you won't have problems.