Yes, the 1.6 Ghz processor in the MacBook Air is powerful enough to do everything you listed. Keep in mind that processor speed is not everything. You also need to consider the type of processor and how efficiently it does what you need it to do.
By modern standards, a 1.60 GHz processor is pretty slow. Most machines that run at this speed are either older computers or netbooks.
I spoke to a ranch dressing manufacturer and their recommendation was that if the dressing was out less than 24 hours, it should be fine. Commercial salad dressings are highly acidified, which would prevent or greatly slow bacterial growth. You may see some change in texture.
Whether it's raw or cooked, fish can safely sit at room temperature for up to two hours. This time reduces to one hour on hot days when the room is above 90°F. After this time the fish should be discarded or returned to the fridge and thoroughly cooked the next time it is used, to ensure the fish is cooked through.