1. You just need to load the installer using a fakesigned IOS. 36 and 249 are typically signed off, especially if you've previosly followed one of our guides.
2. See 1.
3. The world will implode and Charlie Sheen will become King of the Imps. Seriously though, no.
It sounds like it's been a while since you've modded. Check out the latest versions of our softmod guides and compare syschecks with your own, and if yours is radically different then consider following the guide to update. You can choose from any of them that fit your firmware, and this is a pre-emptive suggestion to keep your Wii truly up to date.