Spoliers seen on the pictures are Roll Spoilers, which on the DHC8-100, depending on Mod Status, can be used as groundspoilers (rollspoilers in grnd mode) activated by WOW on all wheels, and Pwr levers below 12 deg above Flight Idle.
In flight they provide roll controll together with ailersons.
While lining up for departure flight/taxi switch is selected to flight, and spoliers will extend until Power levers are advanced.
Some aircrafts also have separate Ground spoilers which are located more or less behind the prop (not outboard as seen on the pictures)
For the main landing gear on the dhc8, they have a fuse pin which is designed to break at a certain load, to prevent further damage to wing and fuel tank. MLG will collapse and be pushed up through nacelle.
This fuespin is prone to break if ac is touched down with excessive crab angle. The dhc8 should be landed wing low and aligned with rwy cl.