I'm no expert with cactus IDs, but the Haworthia looks like it could use a bit more water, looks like some leaves are withering so that's my guess. Are the leaves a bit softer to touch? How often do you water them? Make sure the soil is not peat-based and I think your plant won't mind bigger portions of grit in there.

I think the 1st pic is a Hylocereus . Its commonly used as a rootstock for grafting other cactus to it. It may be getting sunburned, I have one just like it that is turning red from overexposure to the sun. I always keep an eye out for them in the big chain stores in case they knock down the price just to get rid of them. They are pretty hardy and are an industry standard for grafting.