can I put washers on my lug nut studs for "home made wheel spacers"?
Nope. The studs are not meant to have the pressure on them from washers. There are spacers you can buy, but they Are only for about a 1/2" space. Www.jcwhitney.com
Safely ? - don't sound like it
Not a good idea. Go to a tire store and have it done right. If your wheels don't fit, you need different wheels.