Variegated sycamore maple (Acer pseudoplatanus variegatum). Multiple cultivars, yours perhaps grafted cultivar 'Leopoldii', which is noted to often produce variegated seedlings, or perhaps a similar but independent introduction. If yours is fruiting you might try growing the seeds, otherwise you would have to gather budwood and have it grafted for you - or try the whole procedure yourself.

That definitely looks like a Norway Maple. Acer platanoides, a variegated cultivar.

Norway Maples are invasive here, even though Lowes and the Home Depot sell tons of them each year, and everyone has one (that's probably why they are now invasive).

Don't feel too bad about cutting it down. If you insist on cloning it, you would have to graft a branch onto a root stock of a regular Norway Maple. Maybe that's too much to ask for a newbie..? (Hey, I've never grafted trees before either). Trees from seed won't look like your parent tree.

Although I'm a "tree-hugger", I have learned that there are some trees that you shouldn't feel guilty, at all, about removing. This is one of them.

Acer macrophylla is a native maple (if you want to replace it with another maple).