Short answer is no, AFAIK.
However, if I may go beyond your restriction of "na-adjectives", things get interesting.
For example, daikon だいこん is pronounced as deekon でーこん. Daikon is not an adjective, but you see a similar pattern as sugoi / sugee.
BTW, this is not limited to Tokyo-ben. We say Okayama-ben turns "daikon taitoite" だいこんたいといて （...
Yes, 難しく and 考える are grouped here. The ku-form is a form used to modify a verb, in other words, it works like an adverb. See this article, too.
速く走る to run fast
よく考える to think hard
弱く叩く to hit/tap lightly
格好良く踊る to dance in a cool manner
Likewise, 難しく考える means "to think in a difficult/complicated way".