Sounds like you at least have some substandard ground issues. Most likely at the rear light fixtures. Also, crooked bulbs in the sockets could cause parking lights to come on when you hit the brakes... the bulb itself completing the circuit to the front parking lights if the lead nub on the bulb for the brake light filament is touching contact for the tail light.

I'd also say you've got other issues.. one of which could well be a vacuum problem in the brake booster.

Couple things I'd start by doing... clamp off the vacuum line twixt teh engine and the brake booster and see if it still dies.

Disconnect the brake light switch under the dash... or maybe just pull the fuse and see if that helps.

Check all the big ground connections under the hood. Both from battery to chassis, and the ground strap from chassis to bellhousing.

Could also be wiring in the steering column as you suggest, or maybe a problem with the (unobtainable) ignitions switch itself.

Good luck...
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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC