Does it make the implementation analyst less dependent on app developers?Does it give access to app codebase to pick and define variables? One of my goal by switching to Launch is to be less dependent on development team, e.g. triggering trackstate and assigning a screen names in pages report withou...

Are there any recommendations for a visit expiration?I know 30 mins used to be a standard for the web, however is that what is prevailing currently?Also specifically for mobile app, what is the suggested visit expiration?

In this case, you should use Page Velocity metric and it is calculated as Page View (Participation)  divided by Visits.

Create segment at Visitor level[Container - VisitLast Touch Channel = Social Mediaand Abandoned Cart Segment] AND THEN WITHIN 1 VISIT[Container - VisitLast Touch Channel = Emailand Payment Confirmation exists] Once created, check the number of visitors for this segment.