Can a VP turned P be elected for two more full terms?
Presidents are limited (by Constitutional Amendment passed after FDR won a third election) to being elected to two full terms. A term is four years, so the max in that case would be 8 full years. However, if you are a vice president and take over the presidential office more than half-way through the term, you are allowed to complete that term without it counting to the maximum you can serve. So in the (traditionally held) maximum scenario, a VP would assume the presidency two years into a term, then serve 2 full terms afterwards, for a total of 10 years. This hasn't actually practically happened, but it's possible.
There's perhaps some nightmare scenario where a few people can shuffle themselves in and out of the office without serving full terms but that would require a lot of coordination and at that point you might as well just rip up the Constitution anyway.
Could Obama have been picked as Biden’s VP?
Probably not, but it depends on the interpretation. The 22nd amendment (the one from above) limits presidents from being elected more than twice, but technically doesn't limit becoming president through the line of succession. Some would interpret the 12th amendment, which originally set up the procedure for President/VP elections, as saying that anyone who is ineligible couldn't be president, thus superseding the technicality argument. But ultimately this is a grey area that would have to be challenged and then decided by the Supreme Court. Since no one has tried, we don't really have a definitive answer.
With that being said, there doesn't seem to be anything barring Obama from serving in a role that's on the presidential order of succession, he would just be passed over if that succession came into play. A real example is Mitch McConnell's wife as Transportation Security Secretary, which would include her in the succession order, but since she's Chinese she just passed over for the next person in line. So if Obama wanted to, say, run for a House seat and become Speaker, he would totally be able to and just (probably) not be included within the order of succession. So I don't think there's anything barring Obama from running as Biden's VP or assuming the office, it's just that the most important job of a VP is being first in line when the President dies/resigns.
Obama as a VP would create a legal challenge which would likely result in him retaining the office of the VP, but not being allowed to step in as President. Since the next person in line is the Speaker of the House (who could change parties every two years instead of four for president) could potentially be from the opposite party, so it's within the political interest of the parties to have an unquestionable immediate successor in place.
Not American, can a VP turned P be elected for two more full terms? Does it work the other way around? Could Obama have been picked as Biden's VP?
They can only serve up to 10 years. So if Biden dies 1 year in she can only get 1 more term. If he dies two years in she gets 2.
Obama can't be VP because the VP has to be eligible to be President.
Presidents are limited (by Constitutional Amendment passed after FDR won a third election) to being elected to two full terms. A term is four years, so the max in that case would be 8 full years. However, if you are a vice president and take over the presidential office more than half-way through the term, you are allowed to complete that term without it counting to the maximum you can serve. So in the (traditionally held) maximum scenario, a VP would assume the presidency two years into a term, then serve 2 full terms afterwards, for a total of 10 years. This hasn't actually practically happened, but it's possible.
There's perhaps some nightmare scenario where a few people can shuffle themselves in and out of the office without serving full terms but that would require a lot of coordination and at that point you might as well just rip up the Constitution anyway.
Probably not, but it depends on the interpretation. The 22nd amendment (the one from above) limits presidents from being elected more than twice, but technically doesn't limit becoming president through the line of succession. Some would interpret the 12th amendment, which originally set up the procedure for President/VP elections, as saying that anyone who is ineligible couldn't be president, thus superseding the technicality argument. But ultimately this is a grey area that would have to be challenged and then decided by the Supreme Court. Since no one has tried, we don't really have a definitive answer.
With that being said, there doesn't seem to be anything barring Obama from serving in a role that's on the presidential order of succession, he would just be passed over if that succession came into play. A real example is Mitch McConnell's wife as Transportation Security Secretary, which would include her in the succession order, but since she's Chinese she just passed over for the next person in line. So if Obama wanted to, say, run for a House seat and become Speaker, he would totally be able to and just (probably) not be included within the order of succession. So I don't think there's anything barring Obama from running as Biden's VP or assuming the office, it's just that the most important job of a VP is being first in line when the President dies/resigns.
Obama as a VP would create a legal challenge which would likely result in him retaining the office of the VP, but not being allowed to step in as President. Since the next person in line is the Speaker of the House (who could change parties every two years instead of four for president) could potentially be from the opposite party, so it's within the political interest of the parties to have an unquestionable immediate successor in place.