You’re assuming the collatz conjecture holds, which is unknown.
But even if it does hold, you do understand the second problem, right? 1 can not possibly be the outcome, because whenever there is a 1 in that infinite loop, it is followed by a 4. And if 1 is the outcome, then it wasn’t done infinitely, because otherwise there must have been a 4 afterwards. The same argument holds for 4 and 2 as well. So we’re stuck in the reality that it would have to be one of those numbers, but it also can’t really be one of those numbers. It’s paradoxical.













It really depends. For example, if you walk 1m, then 0.5m, then 0.25m and continue infinitely, then “after infinity” you will have walked exactly 2m. This is the classic ‘Achilles and turtle’ example and works fine if the value converges. It’s just mathematics.
There is only a problem if the value diverges. Imagine the step example, but on even steps, you raise a blue flag, and on odd steps you raise a red flag. Now the question what flag is raised “after infinity” is impossible to answer. It clearly should be either red or blue, but it also can’t really be either, because that would mean infinity is either even or odd, which makes no sense.