For sea kayaking and hiking one of the best areas is where we have our base in south west at Ilingas beach (see Google map link).
We can offer 2-3 day trips (like this one) starting from the same area and also an overnight trip (2 or 4 days).
Our multi day trips are listed in this link.
For rock climbing unfortunately the best areas are a little bit far from south west and more specific in the region of Heraklion. You will need to rent a car if you can't meet us in Heraklion city as we offer transfer only from there.
All the details about rock climbing can be found in this link.