You may lower the gear to slow the plane down and make handling easier. Flaps and gear are structurally unsound at high speeds. They fall off if you exceed approximately 400 knots while they are deployed. Missing flaps make good landings difficult. Missing gear makes a good landing impossible.
Flaps increase lift, increase drag, and decrease stall speed.
Spoilers decrease lift and increase drag dramatically. They are most useful in dissipating excess altitude without increasing speed. While spoilers are deployed, it is difficult to recover from a stall. Several controls allow the viewer to alter his view of the world. The viewing angle is displayed on the windshield.