1. No, it's mixed in with every other mod. If you want to easily delete a mod, make an entirely new copy of DF for it to live in.
2. You should never, ever overwrite a previous version of DF with a new one, especially with such an update as this. Saves aren't going to be compatible, anyway.
3. Depends on the version. This next version has a total tree overhaul, but everything else has default values, so it shouldn't be too bad.
4. No; again, the easiest way is to have a separate copy of DF for each mod.
Mods, in most instances, are sets of .txt files that can be altered using various tokens.
New .txt files can be created within the folder, and used by the game, but some mods alter the pre-existing files, which can make reverting them difficult.
It is best to keep a copy of the original raw folder in case you need to "reset" the game, though this may not be necessary, depending on the extent of changes caused by the mod.
Saves are usually in-compatible with newer versions of the game, but newer versions come as full installs, so you won't need to worry about removing mods. Updating them may be tricky, depending on how many things change between releases/updates, and if/how many new tokens are introduced.
Toggling mods isn't possible in most cases. A few mods, such as Masterwork, have their own interfaces that allow you to toggle options on and off though.
Most updates are save compatible, but major updates like the next one won't be. Most mod updates are not save-compatible.
got it! thanks to you gentlemanly overseers,
i got the newer Lazy Newb Pack which I will be holding onto as my failsafe..
other than that I grabbed a copy of Masterwork, too, as aside from novelty and for playfulness the other ones i looked at just kind of seemed lacking (aside from the replacement of dwarven animals to underground animals which was unfinished and some mythical creature additions). if you guys have any good suggestions, i would love to hear them.
this is my first time around the modding thing
thanks again guys, you've been a great help.
pillars of the mountainhome, you.