Yes, because "osoba" is a gramatically feminine noun what doesn't mean that the person is a female. Similarly, "człowiek" (masculine noun) can refer to a human being of any gender.
I was recently wondering something similar. I said "Jesteś najmilszą kobietą" to a woman because it seemed weird to say "Jesteś najmilczym człowiekiem". This was after she complimented me for attempting to learn Polish (true story :-)). Was i right?
Am i the only one having a hard time pronouncing three consonants together? " t w s" is quite a mouthful. Will people still understand me if I remove "w" from the sentence?
Probably yes, as it wouldn't resemble anything else anyway. But maybe it's better to make an a bit bigger stop between "jest" and "wspaniałą"? Also it may help to think of 'w' as devoiced and make it 'fspaniałą' in pronunciation.
You're hearing the beginning of the word "jest". The way "jest" is pronounced can sound a slightly prolonged "i" sound after "on". It's tripped me up a couple times too.