In a strictly technical sense if you source ice in space from something like a comet and bring it down slowly with something like a space elevator it would help a tiny bit. However the amount of effort would be much better spent on either fixing things we are doing or going for one of the crazier but valid options like building satellites that shade something like 1-2% of sunlight etc.

I think very, very slightly warmer, for solar panels. The solar panel captures energy that's hitting the earth and would otherwise partially heat it up, and to some degree reflect back into space.

Since the energy would normally heat up, if you spend it doing refrigeration instead, it'll ultimately produce the same amount of heat from energy losses - you can't produce more energy than you have coming in. If I'm correct about that then, the only increase in warming you'd be getting would be from the small amount of light that would otherwise reflect into space, but was instead captured by the solar panel.

No idea how this works out with wind turbines, since the wind has to be getting energy from somewhere and putting it somewhere, but no idea if it ends up dissipating as heat (from friction?).

I don't know. I'm not sure if the refrigeration cycle is neutral. Even if we ignore the energy source, creating cold also creates heat, so that ice might just about counteract the heat generated to create it.