no. just no. stop and think.
janna will have 550 auto range and no ad scalings on any of her abilities.
no attack speed steroids either. 550 range is VAYNE range which is really short effective dps range. vayne is actually trash because of this despite the fact she is absolutely busted in terms of dps/mobility and even she has a form of self peel (condemn)
Janna is not "dangerously close" to being an adc. if you want self peel you would go tristana who is mobile, has resets, burst damage, longer range, attack speed steroids, her abilities scale with ad, and some of the best self peel for adcs in the game. or xayah who also attack speed, damage steroids, untargetability, wave clear, poke, and burst damage.
the only enchanter who could theoretically be close to being an adc is lulu and thats because she has an attack speed steroid and an auto enhancer in pix. her W can also be used offensively in a 1 v 1 to win that as well.
however, lulu only has 500 range, even less than Vayne and zero abilities that scale with AD that she can use to harass with or even team fight with. which means her team fight and laning effective threat range is 500. which is trash. thats lucian without the mobility or damage.
no. just....no.