As far as stage 2 goes, Mystwalker had posted in a thread somewhere that he used the flag -k 4 for gmp-ecm for a 1024MB system (which is what I have), so I'll be using -k 4 when I finally get around to crunching all these stage 2 curves. [/B]
Actually, the -k 4 option is not necessary right now - it comes into play at the 55 digit level, when bounds (and hence memory requirements) are much higher. For the 50 digit level, computers with 256+ MB RAM should work well without it and be ~5(?)% faster.

Apart from that, everything seems to be perfect.