I just completed my wifes visa application for entry to Switzerland. It seems rather simple compared to the one for the UK. Should I attach any supporting documents to this application? Like hotel reservations, plane ticket, bank statement, etc.

Required supporting documents can be found by clicking on the relevant link on the right hand side of this page.

From my experience with the Swiss Embassy, you will need to supply a detailed itinerary including flight bookings and details of where you will be staying on every night of your proposed stay in Switzerland, If you are staying in hotels, you must supply copies of the reservations. If you are staying with friends in Switzerland, they must supply certification from their local gemeinde (= amphur) that they own or lease an appropriate residence. You must demonstrate sufficient funds for your stay and, most importantly, you must supply evidence that the applicant has compelling reasons to return to Thailand at the end of your visit. Details of your wife's ties to Thailand (immovable assets, employment, close family) are key. If you live and/or work in Thailand, then include evidence of your ties as well.

The form is a variant of the standard Schengen Zone visa application. Don't let the simplicity mislead you - the Swiss are quite tough. If a visa is granted, don't be surprised if it is a single entry valid for the exact days of your proposed stay.