How do i keep my ipaq rz1710 running as clean and fast as possible? programs to use, ways to keep it cleaned out? How do i defrag, system check or anything like that? is hard booting frequently good?

I use space reclaimer to clean up daily. You should also check out mem maid. I also soft reset every couple days. I have never done an intentional hard reset and would leave this as a last resort or maybe once a year as maintenance.