Big macro fan here and a glasses wearer too... I'm not sure why you're afraid of scratching your glasses, my lenses have had all kinds of nasty impacts (thank God I had my glasses on at the time!!) and they do not show any marks, modern lens materials are very robust and hard to mark.
AF is just a big no-no for macro work, if you're struggling then switching to LiveView can help as you can then crank up the magnification to aid you. The best bet though is to nail the "rocking backwards and forwards" technique of focussing... Basically get the focus approximate and the gently move backwards and forwards until you've got perfect focus then hit the shutter release. It's worthwhile mastering this as it's about the only way to shoot handheld above 1:1 and it allows you to get shots for focus stacking as well.
As the others have added flash is a must, I always shoot at around 1/160 to 1/200 and manually adjust my flash power to suit the conditions.
I am still debating on if I should return the Non IS and get IS. Are you shooting with IS? In your opinion at 1:1 will IS be the cure all?? Sound like it might help a little but at 1:1 any movement will be an issue??
Think I am going to see if monopod helps