If you are wanting CH denominated savings and a secure as possible ie not investing in the money market or shares then you will be looking at 3/4% and little more unless you are investing in a fixed term saving. You cannot reasonably expect to get 3% interest when you can borrow for 2.8%!

Due to the length of the investment you will find that banks have pretty good income oriented fonds. These are ones designed to ensure you get a minimal risk low return investment and you can reasonably expect 2-2.5%p.a. over a period of 3 years. Any Bank will be willing to show you such products.

When you say long term what do you mean. If you are for example intent on living in the UK in 15 years time ie very long term then you would be very well advised to have a UK savings account. I know the Halifax is paying me 7% at the moment on a fixed term scheme and here you then remove currency risk.

With reference to BVG and IIIa. You can pay 6192 per year into your 3rd pillar which is tax efficient and is pretty risk free. When you receive your pension statement every year you will see a column which states how much more BVG you can invest ie you make a voluntary additional contribution. I think it is at this juncture worth saying there are only limited ways to access your money once you take this route but you will get 2.5%!