Due to Batman's strategies, tactics and desire to utilize fear as a weapon against evil, it would have made greater sense for Batman to become a Yellow Lantern; however, what would have truly been a revolutionary twist in both the Batman and Green Lantern mythos would have been if Yellow Lantern/Batman had truly mastered the yellow lantern by battling and defeating the Yellow Lantern entity thus making the ring his own by locking it in a pocket dimension from which he is able to draw upon its energy and utilize it for his own purposes. But, I do not envision a corrupt Bat/Lantern; what I envision is an even more terrifying, stalwart and strongly principled intergalactic Dark Knight that is a DC rendition of Space Ghost. The Bat/Lantern story line appeared in DC's Elseworlds that are parallel time lines where events that created certain characters have been altered in some significant way that creates a different outcome; while leaving the character essentially the same.
This particular story premiered in 1994 and was never continued despite the fact that many fans badly wanted a conclusion to this story -- a story that many fans would have been truly "dope". The closets we get to what such a Batman would appear to criminals or those committing evil was displayed in the Video game story appearing on YouTube entitled the "Batman Arkham Knight" published on Jun 28, 2015. This is the link to that video . THe advantage to this scenario is that Batman is not under the control of the Guardians and is able to truly become a darker counterpart to Superman. My suspicion concerning Batman's future is that Batman will eventually have to be upgraded in some regard in order to battle various metahumans and stave of the effects of aging. My favorite scenario in how this could be done, yet remain firmly within the Batman mythos is by creating a story in which the effects of Bane's Venom formula and Lazarus pit elements are combined and permanently effects Batman by giving him abilities similar to those of Dead Pool or Death Stroke which would not lessen the physical dangers that Batman faces on a nightly basis; in-fact it would increase Batman's ability to terrorize criminals to an even greater degree.
To end my opinion on this piece, I will state this. I would like both fans and DC Comics to admit that the thought of Batman having a successor is DOA concept. From the time of his inception to the present , June 1940 - November 2016 a period of "OMG" 76 years almost 80 years! In that time, Bruce Wayne has always been Batman, let him stay Batman and create a means of his remaining Batman. One effect of the combination of Venom and Lazarus Pit elements would be a Brace Wayne that whenever he is killed he reverts back to the age that he was when his parents were killed by Joe Chill, then ages normally until he reaches and dies of old age only to repeat the process; however during this time he develops abilities similar to that of Death Stroke's. I believe that his would make Batman even more appealing to fans while maintaining his mythos; while locking him in a "never ending story" of death, tragedy and conflictual triumph on his path to becoming Batman especially if he was forced to watch his loved ones die either of old age, disease or brutality. This to me would be the ultimate Batman!