AutoSPInstaller will automatically create an application pool called SharePoint Hosted Services and use your default App Pool account. Same as Secure Store, Excel services etc.
The SyncConnectionAccount has to be the SharePoint Farm account otherwise its not going work - the service won't provision.
Bit of advice before you setup the User Profile Service - have a good read through this guide (http://www.harbar.net/articles/sp2010ups.aspx), the User Profile Service requires additional configuration otherwise the sync service will fail to start.
The SyncConnectionAccount has to be the SharePoint Farm account otherwise its not going work - the service won't provision.
Bit of advice before you setup the User Profile Service - have a good read through this guide (http://www.harbar.net/articles/sp2010ups.aspx), the User Profile Service requires additional configuration otherwise the sync service will fail to start.