Although you could pipe cool water through the radiators, it's an ineffective form of cooling compared to blown-air systems, and retro-fitting a blown-air system is much more costly than a heating-only heat pump.
Once room and floor temperature match, condensation doesn't occur anymore as long as you keep it running.
While our house is relatibvely small and we kept the units (which also do heating as well) confined to the main living space, it wasn't especially burdensome. The bulk of the work was installing the behemoth of a hot water tank!
Daikin (and presumably others, but they're the ones we went with) do have integrated tanks/heatpump internal units. It might be worth having a think about your actual needs and it may be that there is a solution.
My experience with electric hot water taps is that they've been universally awful and only a last resort, but equally the state of the art may have moved on since I last looked!
I'm currently investigating options for kitchen sinks and such. It feels quite silly to have a long length of pipe leading from a central source for a small amount of warm water to wash my hands.
There's a limit: you can fill a medium saucepan with boiling water, but large/industrial-kitchen pans will exhaust the boiling water and you'll need to wait for the next batch.
It's fine for general household use.
However it will not cool like an A/C unit, only something like 5°C reduction. This can be enough to get a decent night's sleep during a summer heatwave.