Off Road in Switzerland
I live in switzerland.
There are not many off road tracks in switzerland, i know there are some in the Jura area close to the french border, don't know where exactly though. As for the alps you'll be hard pushed to find much. The interlaken area is great, Zermatt is beautiful, and the italian part is nice, also Luzern is worth a visit and perhaps Zurich, but I would skip the cities and do Interlaken and Zermatt. the motorway thing will cost you 40 CHF for the whole year, buy it at a petrol station.
Switzerland is tiny, I regularly go from Zurich to Lausanne for dinner, a friend of mine owns a restaurant in Lausanne and I live in Zurich. It's a 2 1/2 hour drive in a car and about 3 hours in a big massive 130 Defender.
Perhaps going over to the eastern area Graubunden would be good too if you like the mountains, the National park is over there, it's called "the national park".
In March there will still be a fair bit of snow higher up in the mountains.