It depends on the person who made the mod. some modders will get right on it to update it but some are lazy and may never update it.
Most will not work in a newer Minecraft update with out being updated itself. You would have to ask the maker of the mod you have now. Only they will know. Every mod is different. Depending on the mod it could just take a day or so or weeks to update the mod so have patience.
The Ender Dragon is a part of Minecraft, not a mod. You probably need to update Minecraft.
To update a mod, you will have to go to the website that you've found your mod. Redownload it and re-install it.
The mod developer will need to update the mod to be compatible with the new Minecraft version.
If you had a 1.3.2 mod and you want it to be in 1.4.2, you have to download the mod again when it's uploaded. If you don't use the correct update for the minecraft version, your minecraft will crash and you will have to force update it which makes a new minecraft jar.
You need to update your texture pack to the same version as Minecraft.Every time Minecraft updates the game it will break almost every mod/texture pack so the mod writers have to update them to run right again. It can take hours or weeks depending on how large the mod or texture pack is to update them again.
No, you can't take one item from a Minecraft mod unless there is a separate mod which contains that one item.
You will need to reinstall the mod. Make sure you use the correct version of the mod.This is because 'Force Update' redownloads the original Minecraft files, without any mods.
Unless you work for Mojang, I don't think you can make an update. But, what you could make is a Mod.
Usually no, most will either crash Minecraft or will not work. You have to wait for the Mod maker to update to the latest version of Minecraft unless they say other wise. It may take a few hours or a few weeks to update mods.
Yes, they will. You just have to wait until the official mod creator comes out with an update.
The only way to delete mods easily (when not using a mod installer) is to force Minecraft to update before you log in to Minecraft go to Options and Click Force Update, then log in Minecraft will re-update itself to the current version