If there are checked bags and AirBaltic won't interline, then the OP will have to clear customs as Switzerland is not in the EU
The EU is irrelevant.
The Schengen Area (for imigration) and the European Customs Area (for customs) are relevant.
Both Estonia and Switzerland are in Schengen, so the flight between them will - for immigration purposes - be free from controls upon arrival.
Switzerland is not however part of the Customs union, but as we all know customs in Europe is invariably a walk through process (being intelligence and risk lead). And the customs process does not depend upon your passport.
Accordingly I'd have zero customs concerns about this flight.
To me it is flight times that are the concern, not airport.
So, scheduled arrival 0910
Scheduled departure 1125
I don't know the route, if it gets in early etc. I'd assume it arrives on time.
0910. Even if it landed on the dot, you might not be getting off until 0925.
If you were checking luggage, and needed to retrieve it... normally not that bad in Zurich, but it could be 15 mins (you will be walking during this time too).
Check your insurance, check what it requires for a non-through ticketed connection. If it will protect you, then obviously do it. But if it's not clear, I don't think 2hrs 15mins is appropriate for a non-through ticketed connection to a long haul flight.