If Obama's numbers stay the same by the time election night rolls around, he won't be nearly popular enough to give Hillary any kind of boost. Not to mention that she has massive issues when it comes to public trust and gives off an insincere vibe e.g., "We were dead broke", "I told Wall Street to cut it out". Not exactly the best recipe for success.
Obviously you have no idea what you're talking about. Obama currently has his best numbers since the beginning of 2013.
Obviously you see one or two polls and think they indicate an overall trend. I look at the RCP average which has him at 44.5% approval and 52.1% disapproval, which is the lowest it's been since August.
That is a beyond solid number for an incumbent President in his second term.