All of them? No. Pulse-start metal halides can only work in a vertical-base-up configuration. Horizontal bulb wall-packs aren't pulse-start, and horizontal bulb ceiling fixtures can't be converted to pulse-start.
Any wall pack you buy (horizontal mounting) are pulse start.
Initially, yes, but they lose much of their light output long before their end-of-life, by my observation at least 2/3rds at their rated life. CFLs lose very little of their rated light output over their life.
This doesn't agree with the information I've seen but it's difficult to dispute your observations. Dirty fixtures are probably more likely to get cleaned because you have to change the cfl lamps more often.
Or you can convert to T5 or T8 fluorescent fixtures and have the same lumens per watt as a pulse-start metal halide and no maintenance for at least 30,000 hours.