Hot pixels are normal on every sensor. the only way to remove them is to take dark frames.
Dark frames are subtracted from the image via stacking. The camera can do it with noise reduction but as you say it's another exposure and time lost.
Getting into astrophotography is a steep learning curve, even if you only want to take simple wide field images.
If you do not have a mount that can track the night sky you will be limited to around 30 secs exposures depending on the lens (look up the rule of 500).
To get the best out of any image, take multiple shots all the same exposure, take dark frames and also flat frames, stack these images in a good astro stacking app then edit the result.