Will other makes of lens will fit on a canon?
Yes, with FD to EOS(EF/EF-S) mount adapter
Will the Canon 35-80mm lens work with the Canon t1i?
Yes. If the lens is a EF or EF-S lens, it should work fine with the t1i
Will a wide angle lens from a Canon G6 fit a Canon G9?
there are special memory cards for canon elph digital cameras
Will your Canon 70-210 mm FD SLR lens work on a Canon digital?
Yes you can use it but you need a FD to EOS adapter.