That sounds like a DSC unit issue. I cannot think of anything other than the control unit that would lock up brakes. The unit is not cheap.
The soft pedal can be a bunch of things. You may have boiled the brake fluid (moisture in lines turns to steam) which will give you a soft pedal. I would start by replacing the fluid and if that does not work then try a rebuilt master cylinder.
Straight lines are for fast cars...turns are for fast drivers
'04 M3 - track
'06 650i Cab - daily driver
'02 Highlander - kid hauler
'01 330Ci - winter beater