I have yet to see anyone who can brick their phone just by rooting it. Rooting is completely safe if you follow the instructions. It's what you do after rooting that messes up your phone.
First of all, never remove google talk. Android Market utilises a component of Google talk.
Do not flash roms unless if you know what you are doing. Also, unless if really necessary, do not apply lag fix.
Before removing a default app, try freezing it first. Use your phone like that for a few days to make sure it is completely safe to remove the app. Some apps cannot be restored once removed.
Settings, gallery, music player, etc. Some of these apps seems to be necessary for background processes. Killing them only means your phone will have to load them again almost immediately. If you notice that some apps reload themselves continuously, just leave them alone.