That is my question, yeah. This isn't a timeline or a project or anything just me being curious. Thanks in advance!
What other nations were in a good position to take advantage and attack Rome on other fronts?
The underdog can always use allies whether formal or just "The enemy of my enemy ".
The second one it is possible; Rome had a big resource and manpower advantage, but Hannibal's campaign into Italy demonstrated its vulnerability, unfortunately he didn't have the men to capaitalize on it and Rome ultimately just raised more men to replace it's literally massacred armies, ultimately forcing Hannibal to withdraw. Carthage needs to be able to successfully muster the resources for Hannibal to be able to launch a decapitating strike on Rome itself, when he has the oppertunity (in OTL, he never had the men or resources to invade Rome directly which meant even when he was in Italy, decimating Roman armies, he wasn't a existential threat for Rome on a strategic level).