Agh. I forgot about your post. Sorry for being late.
Can I animate in the newest version in Blender and export it to the older version?
No.
Do I need to animate in the older Blender?
Yes. You have to.
How to I give my weapon an animation? (besides just animating the part I want)
You need to create the animation as an action using the action editor. Action name = animation name. If you're using 0.964 (player type and vehicles I think) exporter you don't need to do anything, export normally. When exporting with 0.96b3 (everything else) you press the "Create from actions" in the sequences tab to automatically create the sequences.
Does anything need to be parented? any bones?
You animate the bones. Blockland can't understand object based animations. Mesh is parented to the armature. (Armature is not a bone!) Armature is parented > detail32 > shape.
How do I export an addon with an animation?
Just add in sequences if you have the new exporter and export normally.
How do I make my animation play ingame?
playThread.. playSequence.. state sequences.. I actually have no idea. Search around. I think playThread is for player type animations and state based animations are for items. Just a guess though.
I think this should be added on the OP somewhere, but if you don't want to that's fine with me.
I have plans to write a rudimentary animating guide within a year. It could be finished tomorrow. Or next summer. I don't know when I'll find the inspiration to do it.