Those last two are amphipods. Harmless free scavengers.
I know people say them interchangeably but copepods are different critters - copepods are far tinier and will appear as white specks on the glass. The middle pic is a pinneapple sponge - harmless filterfeeder. They tend to appear in slow water areas (e.g. sump).
can't really tell on the first two pics.
the only bad invert with a "pod-like" name would be a cirolanid isopod. They are big and unmistakable with the beady black eyes. While being seen more frequently in the hobby - overall i'd say it's relatively rare to find. In the past 2 years with my club - i don't think a single person ever posted about one. They attach to fish at night and you should see fish acting a bit strange in the morning (lesions and what not). There was a reefkeeping article about it long ago i think (or at least a nasty ugly pic of a clownfish infested with the isopod).
