Travelling to CH for one week, where and what to hike and climb?

I'll travel to switzerland to visit my brother in Geneva from 1. to 12. May and I plan on climbing and hiking while I'm there, so I'm gonna need a few tips. We would like to stay mostly in one region to do most of our activies, I'm thinking of Valais, Schwyz or Ticino.

We'd like to:
- Go for hikes, possibly one long one up to 3 days
- Sport climb and multipitches, but only easy ones considering he has no experience outdoors.
- Via Ferrata, maybe
- Would love to climb some mountain, but I understand it's too early for that

Questions:
- Which canton would you recommend for us? I.e. which one has the highest density of hikes and climbs available in early May?
- What are the best crags view- and climbing-wise? Any unmissable crag/climb?
- Is it possible to rent the gear?
- Is there some hike that could be done in the high mountains without a guide?
- Anything else you can think of