I tried a lot but i didn't find the word 'Respected' in any dictionary. Some of them just have "respect", so you have to learn the meaning of "respected" from the meaning of "respect", both noun and verb. Respected Definition | Definition of Respected at Dictionary.comThis link says a little about "respected" near the middle of the page. Does this word exist? yes Though it is past participle adjective.
Should we strictly use respectful ? No, "respectful" has a different meaning.