2. Weather and climate are names for the same underlying nonlinear system. This system is the archetype of a chaotic system - predictions of values and corresponding locations becomes increasingly unreliable and then impossible on larger timescales. Climate modelling was the very thing that lead to our current understanding of sensitive dependence on initial conditions.
2. Yes, which is why climate scientists put lots of error bars on their predictions and document carefully the assumptions they're making. To wit, the assumption that we will continue to be as bone-headed about our impact on these systems as we have been. But it is still the case that I have little idea what the weather will be in my back yard in 3 mos but a pretty good idea of what global mean temperature we're looking at in 5 years.