ACR LGT TRACK HDG DEV ON SID OUT OF LAX.

Narrative

LAX 1 DEP SID CALLS FOR 250 DEG HDG AFTER TKOF ON RWY 25; THEN HDG OF 220 DEGS XING THE SMO 160 DEG RADIAL. WE WERE CLRED TO 2000 FT MSL ON THE PDC PRINTOUT; THEN 5000 FT WHEN CLRED FOR TKOF; THEN ASKED TO STOP CLB AT 3000 FT AS WE PASSED THROUGH 2300 FT (CLBING AT APPROX 3000 FPM). WHEN CLRED FOR TKOF WE WERE ALSO TOLD TO MAINTAIN VISUAL SEPARATION ON AN LTT TAKING OFF FROM RWY 25L. THE LTT ROTATED AS WE STARTED ROLLING. I ELECTED NOT TO TURN INTO THE LTT AT THE SMO 160 DEG RADIAL BECAUSE IT LOOKED TOO CLOSE AND I FELT THE SID WAS CANCELLED WITH CLRNC TO MAINTAIN 'VISUAL SEPARATION.' THEN 'COAST DEP' ASKED US 'WHY DIDN'T YOU MAKE THE TURN?' IF SID COMPLIANCE IS THE PRIORITY THEN LET US FLY IT AND ATC KEEP US SEPARATED. ALSO; WITH THE CLB RATE OF OUR ACFT; IT IS AT BEST UNCOMFORTABLE TO OUR PAX TO REVERSE A CLB WITH LESS THAN A 1000 FT LEAD. IF THE AMENDMENT WAS BECAUSE OF IMMINENT DANGER THEN GIVE US MORE INFO. IT JUST MIGHT BE THAT TFC HAS TO BE SLOWED TO ATC'S CAPABILITY TO HANDLE IT. THE TWR AND DEP CTL HAVE TO HAVE THE TIME AND PROCS IN PLACE TO COMMUNICATE WITH EACH OTHER.