Instead of "whatever," you can use words like "anything," "whichever," or "whenever," depending on the context. For a more casual tone, "anything goes" might work. In formal situations, "regardless" or "whichever option" can be suitable alternatives.
You can use kind, friendly, or a word that describes exactly how they are nice, such as generous, forgiving, or whatever word(s) apply.
Instead of using the word challenging you can use the word gifted, special, special gifted.
or
Will, when, why, it, can
I have a stomach ache.
Myself
mixture
are
Another word you can use instead of obituary is "death notice" or "memoriam."
used to be
is, it, in the past.
no "It" is not used instead of he and she...