The main problem with this script is that it bluntly kills a lot of system processes and applications (without even checking if they're actually running), which itself isn't entirely bad, but is a bit "unclean" way of doing it. There might or might not be side effects of running such mass-killall, so basically ymmv. Earlier in this thread I've suggested better ways of finding out which system processes exactly cause long-term issues with memory and performance, and killing those properly in first place, rather than executing tens of killalls in row.

Tbh, initially I felt fairly enthusiastic about this script, yet finally decided to not run it on my device, as I believe there are better ways of regaining N900's performance.