1) No matter who's paying, consider your NEEDS first, then your WANTS. It's cool that your 'rents are taking care of this for you, but whomever's paying, do it once and do it right. Sounds like you're on track and asking the right questions.
2) The MSP is not a "beginner" car, it requires some skills to drive it properly, and has some drawbacks for a younger driver.
3) More power (which the MSP has) means mistakes happen at higher speeds, quicker, and can have tougher, more expensive, and more painful (or tragic) results.
4) Lower profile tires mean a less "progressive" breakaway at the handling limit - this is much harder to control and recover from. 17-year-old reflexes are great, but 17-year old experience means the reflexes may catch it but the action taken may lose it.
5) While the MSP comes "fully equipped" as a performance car, it doesn't allow the learning experiences of "upgrading" a lesser car. These are (IMHO) essential to longer-term driving skill development
6) The MSP comes with non-all-season rubber. If you're in an area that gets snow, you'll need (yes, need) snow tires.
UNDERSTAND: I think the MSP is a GREAT car, but has its drawbacks for a driver early in their learning curve - I was 17 once too (seriously over 2 decades ago - my wife argues that I'm still about 19 tho...). I've driven HARD, and for long miles. I still drive "athletically". I know what you're looking for. The MSP will spank you HARD if you make some learning errors in it. One great choice may actually be be the Protege5 - it gives the precise handling and most of the positive aspects of a MSP with fewer of the drawbacks.
Additionally, it really IS more fun to drive a slower car fast (to a point, of course). You learn more too. I know that sounds wussy, but it's better longer term to learn on a somewhat lesser car, upgrading as you go and knowing what each upgrade does firsthand, than it is to buy one "all built up" with the tradeoffs and knife-edge handling built in and ready to bite you in the buttocks.
(flame) flamesuit on (flame)
I guess that's a long way of saying "They're great, buy one, but if you wreck it we'll all gather in front of your house and throw rotten fruit at you!!!"
...and understand, I mean nothing negative to anyone with this post, nor am I saying in any way that my (or others') driving skills are better or worse than anyone else's. Just trying to provide a neutral assessment of the MSP's strengths/weaknesses as a machine for a younger, and yes generally less-experienced driver.
Impressive as hell that you'd ask around as much as you are, that's great. Whatever you get, enjoy!