Note that 1, 4, and 5 cannot all be right or all wrong; in fact, exactly one of them must be true, and the other two must be false, simply by trichotomy: given any two real numbers $a$ and $b$, either $a=b$, or $a\lt b$, or $a\gt b$, and exactly one holds.
And of course, 1 and 3 cannot both be true at the same time. So you know that there are at least two false statements, and at least one correct statement. So the assertion that "if any one is wrong then all of mathematics may be wrong" does not follow; at least two must be wrong if mathematics is to not be all wrong.
$\pi$ is a transcendental number. That means that it cannot cannot equal a number obtained from integers and rationals through the use of addition, subtraction, multiplication, and root extraction.
Two does not give you an exact value, so it is neither true nor false as written, though if you believe that the exact value of $\pi$ begins as "$3.14$" before continuing, then you may want to mark is sort of true.