Wannabe_fisherman,
Welcome to Fish-Hawk.Net and thanks for introducing yourself. Feel free to ask as many questions as you'd like. I'm sure someone here will be able to handle them for you, and I'm sure you'll get many different oppinions at times.
I"m not sure what Islands you are referring to, but if it's close to the GTA, I don't know if I'd get too excited about the ice being out by March 31, but then again, who knows depending on current and such around these islands if it exists. In any case, spreaders are optional, but if you're fishing Pike, be sure to have a pair of needlenose pliers or something to avoid putting your fingers in their mouths where at all possible.
I generally find that Pike are savages most times. They'll hit large or small baits, the trick of course if to figure out what action will cause them to strike. Spinners, flashers, erradict cranks, or sometimes just a jig and grub may get you a hit. A 12" leader should be plenty, but you can go longer if you'd like. I recommend snap swivels and ball bearings like Penn5 said.
Hope that helps a bit. Let us know how you make out.
Cheers,