I daily drove a Boxster for years -- there is actually a lot of space, you just have to get creative.
While you can't do an HPDE yet -- look for
Find one of these events and sign up -- you'll love it and it will make you a safer driver.
https://streetsurvival.org
As everyone else mentioned -- the blind spots are bad on convertibles -- but with the top down
you will be able to see a lot better.
I would not waste my money on a hard top -- it does not help from a visibility perspective.
A boxster is light an nimble -- and a pretty tough little car. I race a couple.
You do have to be careful in the wet -- until you get comfortable driving --- remember the back end will want to step out -- so learn about weight transfer and teach yourself to be smooth with inputs and "don't lift!"