These reproduce either by cuttings or from tubers (the little white ball-like things that form in time down the length of the growing vines). I haven't done well w/ cuttings of this myself (have also heard/known of folks suggesting pegging down the cuttings as they're coiled in the pot (w/ bobby pins, papers clips, bits of pipe cleaners, etc.), to ensure contact btwn the leaf/root node & the mix. I've had better luck cutting back a cutting that has a tuber on the end & planting the tuber in the mix. I see you're leary of cutting back a long vine, but you'll have to if you want more of the plant. You could cut one vine w/ the tuber at its top, plant the tuber, just barely under the mix & then take a couple of cuttings from the rest of the vine. This way you only cut 1 vine but have benefit of having 2 or 3 pieces to try to root. Good luck & enjoy, fun plants.

How often are you watering? Are you letting it dry down completely between waterings? How much light is it getting? Are you using any fertilizers? If so how much and how often? These two threads will help you, take the time to read them. If you still have questions, we are here to help. Container Soils XXII https://www.gardenweb.com/discussions/2842847/container-soils-water-movement-and-retention-xxii Good Growing Practices - An Overview http://forums2.gardenweb.com/forums/load/houseplt/msg101400289284.html

The stalk borers don't usually attack fruit. it's really common for fruitworm or other caterpillars to get inside fruit, though. Fruitworm moths usually lay their eggs around the calyx,and the baby fruitworms bore in under protection there, and the larger holes you see elsewhere in the fruit that look like perfect holes are usually their exit holes. If you're seeing a lot of those, start spraying BT up under the sepals of developing fruit. Caterpillars that attack from the outside in vs from the inside out usually don't leave deep holes but leave damage to the outer wall of the fruit. Next time you cut off a branch that looks like it might have a borer in it, split it lengthwise to see whether there's debris inside consistent with frass. Or you may even come across the borer. You probably know this already, but the borers that affect tomatoes (and corn and other plants) are dull brown/gray moths. They're not the same species that attack squash plants.

I am not so sure about sand making a fast/well drainig mix, if fine. Mixing the soil with sifted perlite in 1:1 ratio is usually better. BUT I don't know what kind of sand you used. It is really best to get rid of all original soil. I am not sure why you say:..."I don’t have a place I can rinse the dirt out"...? You don't need special place, just a bowl with water...Soil left in the water could be usually disposed of down the toilet, but you can always strain it, flush only what comes thru the strainer, and get the rest (bigger 'chunks' of soil) into green bin. I wouldn't rush with ..."doing a nice thorough bottom water today"...Sounds like roots are damaged & they are quite wet, so give them time to heal and regrow. What is recommende is cutting off all the damaged/rotted/dried out roots & letting ends to callus for a bit before planting. NO ROOTS - NO WATER is a good mantra. Plants shouldn't be exposed to strong light for a while, so don't worry about having no hook yet. You should not overpot either, especially if your potting mix is not well/fast draining. How big is the new pot? I have few pots of different ceropegias, and treat them like succulents. Cuttings also root quite well. These comments are based on what you said, and I may be wrong. Attaching a photo or a few often helps.