I don't think there is a chance of roger having at any point the gomu gomu fruit. if that was the case then it would be something which we would know by now. Someone among the old timers would have cared to point this out, it would be extremely significant in regards as to how dangerous luffy is. I don't really have an opinion on whether roger had a fruit or not (the manga has not hinted or alluded to this) but I would prefer if he did have a fruit. It would be significant if he didn't but the manga makes more sense otherwise. BB himself was ready to not do anything with his life if he never found the yami yami no mi and wanted it solely to deal with pesky ability users. Fruits are extremely significant and it would make sense if he had something to fight and defeat WB with other than a sword. Besides, swordsmanship was more in Rayleigh's area, the implication of Roger being a swordsman comes with Rayleigh and him being basically the same type of fighters which is kinda boring.
With luffy oda aimed to having a strong character with a seemingly weak fruit. Perhaps with roger it would be the same, he had a seemingly not to overpowering ability which he mastered to the extreme. Or perhaps roger ate the human human fruit as became enlightened as oda said the fruit would do to a normal man.
