Nihilus's Giga-drain is pretty much insta-kill, and the stun-effect is definitely instantanious so a hit would mean death, anyway - so I was wondering..
While, it is true for non-Force users, who cannot put any defenses whatsoever, experienced Jedi/Sith can resist it.
As of Luke. He can't use electric judgement nor will he have oneness with the Force to have all that overwhelming lightside energy to convert into lightning. And assuming him experience this state during this confrontation would be unfairly biased. Plus, it is darkside power.
Luke doesn't use fold space during combat and unlikely can. The only example in combat is Abeloth during her first fight with Sith and Jedi. But she was teleporting herself, never did objects.
As for Palpatine. Both Force storm and wormhole are channeling powers involving a lot of concentration, non of it would be used in combat as it would lead to silly death.
As of Nihilus. During combat with Surik he couldn't even drain his former apprentice and a non-Force user mandalorian. Though Force drain does work during combat as I know examples confirming it in books.
Regarding Luke and Palpatine's resistance. In Anakin's case he had to find teachings of Kel-Droma because no one in Order ever encountered it nor there was a practitioner of it to learn by practice. But Luke encountered drain on more than one occasion and Palpatine did it himself.
Although, it is implied that no one could withstand Nihilus' drain, he simply was more powerful, than Jedi of that time, even with knowledge of resistance they would be overpowered. However. both Luke and Palpatine are immensely powerful in their own right.
Luke tactic: use Force only for defensive purposes and use only lighsaber for offensive.
Palpatine: offensive powers mostly against Luke. Could try Force lightning agaisnt Nihilus. There is no evidence of him absorbing Force lightning. And as we know Force lightning is not a pure Force, it is energy produced by Force, which is essentially electricity heating objects to extreme temperatures.
Nihilus: he noms. 😄
There's the simple fact that Force Freeze is virtually unheard of in latter eras. Neither practiced nor defend against obviously.
Lomi Plo froze Luke completely in place by exposing his fear, he literally froze in place and couldn't move for a while. Yet, after he got read of his doubts, he didn't give a fohh about all her arcane abilities.
In Crosscurrent Anzat froze Jaden Corr in order to consume his brain.
Jacen froze Aurra Sing in one place in order to save his daughter.
Force Freeze is just another way of calling mind domination, more powerful user mentally forces weaker one to freeze. In game this ability is given to every Force-sensitive playable character and to majority powerful enemies. There is a reason in game victim is shown having dizziness as he experiences mess in his head. How you concluded that it is some entirely unique ability I have no clue.