  We study the effect of electron-acoustic phonon interactions in twisted
bilayer graphene on resistivity in the high-temperature transport and
superconductivity in the low-temperature phase diagram. We theoretically show
that twisted bilayer graphene should have an enhanced and strongly twist-angle
dependent linear-in-temperature resistivity in the metallic regime with the
resistivity magnitude increasing as the twist angle approaches the magic angle.
The slope of the resistivity versus temperature could approach one hundred ohms
per kelvin with a strong angle dependence, but with a rather weak dependence on
the carrier density. This higher-temperature density-independent linear-in-$T$
resistivity crosses over to a $T^4$ dependence at a low density-dependent
characteristic temperature, becoming unimportant at low temperatures. This
angle-tuned resistivity enhancement arises from the huge increase in the
effective electron-acoustic phonon coupling in the system due to the
suppression of graphene Fermi velocity induced by the flatband condition in the
moir\'e superlattice system. Our calculated temperature dependence is
reminiscent of the so-called `strange metal' transport behavior except that it
is arising from the ordinary electron-phonon coupling in a rather unusual
parameter space due to the generic moir\'e flatband structure of twisted
bilayer graphene. We also show that the same enhanced electron-acoustic phonon
coupling also mediates effective attractive interactions in $s$, $p$, $d$ and
$f$ pairing channels with a theoretical superconducting transition temperature
on the order of $\sim$5 K near magic angle. The fact that ordinary acoustic
phonons can produce exotic non-$s$-wave superconducting pairing arises from the
unusual symmetries of the system.
