As Maytag mentions below, the start up sound is the only worrysome in my opinion.
Is the noice like rattle or like screech or something else?
- if like a rattle, the chains / tensioners / chain ramps are a good candidate to cause this: engine out and change the parts. Fine to do as a DYI job and don't have to split the crank case nor take the heads off.
- if like scheech, then good candidate is that the starter motor pendix wheel return is not workign well: very easy DYI to change the starter motor OR take the starter out, open it, clean and relube and reinstall.
I have done both above on my 2001 Boxster and I believe that you can as well.
Here's a good video of the starter noice and how to fix it:
https://www.youtube.com/watch?v=eJ9qnnf2kWU&t=19s