Here's the Bottom line..

Nothing compares to a pure super saiyan's power. NOTHING!. not Gohan, not trunks, and certainly not dabura or crap like that...you people seemed to overlook the fact that Majin Buu ONLY hatched because of Majin Vegeta, and SS2 Goku's battle. If it wasn't for that then he would have never even come close. Second, F trunks is from a totally seperate timeline, meaning he is absolutley not the same person as chibi trunks. Even though the HBTC is the same dimention all around, it still doesn't matter, because they were two totally different beings. They did have the same genetic composition, but they were still totally diffrent beings. Think of it this way, if Chibi trunks dies in the current timeline, then it wouldn't effect f trunks at all, he's still live. Because it's 2 totally different dimentional timelines. DBZ is fucked when it comes to timelines, mainly because it doens't explain it good enough.

Another thing, if Majin Buu did come back in the future, here's the bottom line, and this is totall logic here. Vegeta was as strong as Future trunks at Cell Games. And during Majin buu saga, he trained the entire time, and he almost was able to defeat Majin Buu (the fat one) mind the Majin powerup. NOW!...when you say that Buu should have come and killed F Trunks, you're automatically assuming that he had hatched...but where would he have gotten the power to hatch? Trunks would have annihalated any means of him even remotley begining to hatch before he would even be able to hatch...let me put it in simpler erms...Meaning that Future trunks was MORE then strong enough to take out Dabura, and Babedi EISILY before they even got a chance to do ANYTHING with the Buu ball. Thats it, it's over, F trunks isn't as much of a wuss as you think. (not that I like him or anything)