I think the weed killer in the fertilizer may interfere with the grass germinating. It's generally safe to use on lawns, but only after they're established. It's kind of late to try to seed a lawn, anyway, so maybe your best recourse is to try to get the weeds under control between now and when the temperatures start to drop and reseed then. The best time to reseed is probably sometime between August 15 and September 15.

Check under the deck to ensure grass clippings haven't clogged it up. If you have thick, tall, wet grass this could happen pretty quickly (especially if you are mulching). You may want to bag or side discharge until you get your lawn under control. Start at the highest height setting and then work your way down.

Only a few cacti have leaves, and Easter cactus is not one of them, it is the stem segments you are referring to. Yes, take a few cuttings. If the roots are lost, you will be better off with young segments as old, hardened segments at the base of the plant can be difficult to root. If they survive that is, root rot often causes the segments closest to the soil to die. Easter cacti are sensitive and will often drop segments if they are sick. If you find an Easter cactus puzzle on the floor one day (happened to me twice) you will automatically have a lot of cuttings. Otherwise cut off pieces of 1-3 segments with a sharp knife. Some people root them in water, other (like me) in damp sand or white moss or directly in potting compost. If you do not root them in water the cuttings should heal heal in a shaded spot for a week or so first. Red spots sometimes heal by themselves, but they can also be the result of a fungal disease that will kill the whole plant if untreated. Remove affected segments, just in case.

Updates on my various cuttings These are the ones that cooked. They haven't shriveled up yet (except one, which was growing from a mostly dead leaf already) and I'm not sure I can see any new growth. The roots look almost okay. The same day that happened, I pulled off some Graptoveria Moonglow leaves to propagate and replace the leaves I'd killed. This time just left them on a piece of paper in a box, no water, just indoor light. And look! You can barely see in the photo but the first three on the bottom have some really tiny growth. The biggest has about four roots going out, the second has a single leaf, and the third has a leaf and roots growing. Lastly, dropped leaves I might have grabbed from the nursery, which had already been developing roots when I found them. Top is E. Pearl von Nuremburg and bottom is E. Chroma, which seems to have exploded tons of roots and what looks like three stems with rosettes. The Pearl von Nuremburg is growing slower, but I find the one giant leaf it has funny.