Minecraft – World edit 100 Million Blocks

If the biomes shifted it's probably due to a corrupted "seed" (just a long number) which seems to happen quite easily when the server crash. If you have an old save that still is ok you can get the correct seed from that save, and then edit your current save and set the correct seed.

It's really easy to read and set seeds with LolEdit. You just open the save in the editor and modify the seed field.

If you have explored new areas while the seed was corrupted you might also get problems with "sliced walls". Check my slighty longish answer in this thread for a solution to that.

Well, as it turns out, /sp is just an alias for /superpickaxe. You could easily change this to anything else. Just open the WorldEdit.jar with any ZIP unarchiver and edit the plugin.yml file that's inside. It's a large file, so just do a Ctrl-F and search for 'superpickaxe' to find what you're looking for. It should look like this:

superpickaxe:
    description: Select super pickaxe mode
    usage: /<command> 
    aliases: ['pickaxe', 'sp']

See the line that says aliases: ['pickaxe', 'sp']? Just remove the 'sp' and replace it with whatever you want. That should fix the issues. Then just rearchive the JAR and run the server.