Can you ID these, are they good

[sundance]

Here are three images of things that I have just seen. Can you ID them and let me know if I should try to get rid of them? The last image is not to clear, is this a "pod"?
Thanks

 

[sundance]

Is this a slug or snail, good or bad?

 

[sundance]

Last but not least is this a pod, I'll try to get a better picture. I have them all over the bottom, if they are bad I'm in trouble.

 

[wablondie98664]

the first pic looks like a snail i've seen i'd as a strombus, very benificial and the third pic looks like a pod to me

 

[aarone]

the second is hard to tell from the top. Maybe a nudibranch?
aaron

 

[azonic]

I had something similar to #2 in my previous tank and I believe Bang Guy gave me a positive ID on it.
So here's a bump for ya to hope he see's it.

 

[bang guy]

1 = Strombus maculatus
2 = Need a pic from the side or bottom
3 = Gammarus Amphipod
All good but I can't tell what #2 is from the back.