I was told that my rail pressure was around 1700psi, and don't quote me, but I think the spec is 2400. Turns out my injectors have high loss, but now beyond warranty. I just can't afford to fix it now... can I have the dealer put it back together and drive it, or am I asking for castastrophe? Generally it was running OK, but had some brown smoke & reduced power.

Its not reccomended that you drive it like that but its your vehicle... You won't be able to pull anything without putting the engine into limp mode. If your rail pressure is that low at idle then at max psi it's most likely 15000 or less, spec at max psi is 23000.

Have you had any p0093 codes? or engine limp?