Welcome to the Boxster club. As for your car with a long list of maintenance records, either that's good or bad. Look over your records and denote repairs from maintenance to give you a good overall view of the mechanical condition. You said it is in extremely good shape, that's a plus. I've seen 08's that needed to be parted out, but they where still on the road. 70,000 miles, to me is just getting broke in. New top, that's a big ticket item that's been taken care of. I assume by your stalling it's a stick shift and you may have heard about the IMS bearing failures destroying and engine. I will note that you see this issue a lot with sticks but not so with TIP's. Has the clutch been replaced, if not, then your issue maybe with the clutch, since you have 70K on it it most likely needs to be replaced.
You paid $1310 for for rotors and pads, OUCH. That's at DIY and it could have been done by you in one day for less than $400. $100 for the oil change, good price.
Now, a 60K maintenance requires serpentine belt to be replaced, oil change with filter, air & cabin filters replaced, fuel filter replaced, new spark plugs. You can do all this yourself. The Boxster is really not hard to maintain. We are here for you and the DIY section can be very helpful. Go to Pedro's Garage on the web, he has a DIY section which is very good. Or, Pelican Parts, you can get parts there, plus they also have a BBS for Boxsters.
Mine below is a TIP...and it's more fun than stick. Also, I felt like you, sports cars need to be shifted. Changed my mine in a heart beat after driving a TIP. Never say never.