Originally posted by The Merchant
He was holding back unless you want to claim Luke during that era along with R2-D2 has the durability of the entire surface of Coruscant.
This is how the events unfolded:-
Force Storm power approaches Coruscant from hyperspace route.
"It's coming out of hyperspace..." - Tseb Nllel Whub
...A hyperspace wormhole have opened in the night...and a mighty energy storm emerges!
Force Storm makes contact with Coruscant, damaging the surface where it lands.
With rumbling chaotic fury, the storm sweeps down across the planet's surface!
"It's almost upon us! There's no need for you to die too! It doesn't wants you... It wants me! Leave! All of you or you'll be destroyed!" - Luke Skywalker
NOTE: Force Storm is pulling stuff in it.
R2-D2 joins Luke Skywalker. More importantly, Luke Skywalker and Darth Sidious telepathically connect with each other to enable Darth Sidious to teleport Luke Skywalker to his domain.
And across the vast deeps of space, two masters of power touch minds...One the very essence of Jedi...the other dark beyond darkness
Force Storm pulls Luke Skywalker and R2-D2 in along-with lot of debris.
----
Now tell me ... if Sidious had been holding back, then why Luke forced his allies to leave Coruscant?
Luke's teleportation had been possible because he connected with Darth Sidious and he also protected R2-D2 or perhaps he convinced Darth Sidious to protect R2-D2 as well.
Originally posted by The Merchant
He wasn't trying to destroy anything, those where the sheer side effects of using said power.
This doesn't seems to be the case.
Keep in mind this:
As war raged in the skies and on the surface of the former Imperial throneworld of Coruscant, a hyperspace wormhole appeared in space and made its way to the surface, indiscriminately destroying friend and enemy vessels alike. Witnesses commented on how the storm seemed single-minded, and indeed it was: The Jedi Luke Skywalker was its target, and even as it tore into the surface of the city-covered planet in a frenzy random destruction, it made its way torward the spot where Luke, having recently ditched a captured Imperial Star Destroyer, was pinned down in a crossfire.
Taken from The Dark Empire: Handbook
Originally posted by The Merchant
I'm going to repeat one more time that Palpatine was planning to consume the entire Pinnacle Moon Base with it but was stopped.
This is the only clue:
"...Look below...Look what is happening to your pitiful moon!" - Darth Sidious
No mention of absolute destruction or something else. If you have additional information, you may share.
Originally posted by The Merchant
As for causing damage to Coruscant's surface note the planet sized city is designed to withstand orbital bombardments as well.
Force Storm did damage Coruscant to some extent. But the power isn't so destructive as you are trying to imply it is.
---
Source of quotes highlighted in blue: The Dark Empire (Comics)