Can you prevent a remote wipe from iCloud after it has been issued? I thought I lost my iPhone 4s, so I blocked and told iCloud to erase it the next time it connects. 

Now that I found it, I know that as soon as it gets internet connection, all my information will be gone.

For my luckiness, it is turned off, and furthermore it has received neither wifi nor internet connection. (My phone provider had turned off data before I lost it.)

So, I know my information is still alive.

Now that I found it, I want to backup everything before the unavoidable happens (reseting).

If I turn off all wifi connections, How can I make a backup to my computer? I could uninstall iTunes as well. As the Apple tecnical support guy told me that if it connects to iTunes, everything will be gone.

Can I use it as an USB data storage and just copy everything to my computer?
If your iPhone is not password-locked, you can use PhoneView to extract all of your PIM information. Anything that is DRM-protected will not be available via a tool like PhoneView though. I have used PhoneView to retrieve contacts, photos, and voice memos that users needed to keep. I recommend it for just such a task.