If you're not using a lot of CPU-intensive apps, then you should configure the processor speed to "adaptive"; it runs quieter and cooler for the most part when you're just typing a document, surfing the web, etc.
Though the Celeron-M has only 1 MB of L2 cache, the performance difference vs. Pentium-M isn't that much, if they're both at the same clock speed. For some reason, cache is not as big a deal in notebooks as in desktop processors. I...
It's probably because IBM sets up a hidden partition on your hard drive for a clean factory install as a backup in case something goes seriously wrong and you need to reformat. IBM uses this method instead of backup CDs.
Well, Crucial has this Memory Advisor tool that guarantees compatibility with your computer model. But I don't know if it will affect IBM's warranty...maybe I'll wait until my warranty's over (in a year or so) before upgrading memory.
I'm not exactly an expert, but here you go:
1. Since the R50 probably doesn't support dual channel, inserting a 1GB stick is fine.
2. You should check Access IBM for the exact instructions, but they should be very easy.