Question about the GE

Out of curiosity, beside the Chiss ascedancy and Hutt's space, were there other kingdoms/planets/sectors etc that were not part of palpatine's empire and were indepedent?

Well, the Galactic Empire had half a million planets under its rule and 69 million colonies (according to Wookieepedia, source: The Essential Atlas), and the entire galaxy was composed of 1024 sectors, also according to the Essential Atlas, each of which had an average of 50 star systems, though some had up to 125.

I tried to do the math and it seems like it doesn't add up, but I'm just going off of Wookieepedia, so I would recommend just getting the Essential Atlas.

There were loads of planets that weren't really part of(or explicitly occupied by) Imperial rule -- mostly in the Outer Rim and beyond.