General point: Please ask one question per thread.
Q1 & the crash may be related: Most likely caused by either a 3rd party shell extension or a 3rd party video codec. See the quite Crash, exit or high CPU when viewing a certain directory for advice on tracking it down.
Also, if you have the Qualcomm/Atheros bluetooth drivers installed, the shell extension they install has been causing a lot of crashes recently. Details here.
Q2: Turn off Preferences / Display / Options / Use visual style to draw items (Vista/Win7 only, overrides background colors).
Q3: See Enable/fix playback of various media formats in Opus.