any chance you could post them upright?... I have a very hard time looking at things sideways. They look like Coccothrinax species, though.

Fertilizer most likely has nothing to do with corking, I asked about what you posted. Is that fertilizer ready-made solution or concentrate to be dissolved in water? Instructions for 'squirts' sounds strange to me but anything is possible (I am not suggesting that is your idea either). Questions I asked are about basic needs of succulents: free draining potting mix; container with drainage hole; lots of light; good air circulation. If these are supplied, the plant grows healthy and it is much easier to care for. Your plant doesn't look sick. Corking is natural. Plant is possibly bit lighter color than what it should be, but it is difficult to say for sure from a photo. If there is not enough light, the color usually gets lighter and plant starts to etiolate - stretch, trying to reach more light. It would grow 'skinnier' or with longer parts, and sparse spaced leaves. It will not die but could be weaker. Most important is good drainage: succulents should not have 'wet feet' - that could easily happen if the soil is too fine and it stays wet too long at the bottom part of the pot. It is difficult to tell sometimes, especially if potting soil contains too much peat that appears very dry on surface. Watering plant may seem to be appropriate, but it could be still too wet. If this happens and continues for extended period, it could cause rot.

It doesn't matter. You will get the look with literally any pure white solid surface, and yes, even Corian! What is the rest of your bath, all the materials? The original pic was an Instagram, ( slightly less blurry below ) not Pinterest. Put all your materials together, and it isn't the bench or the curb top driving your love of the inspiration pic.: ) - it might be a hazy photo?

Are the backgrounds of these photos natural fibers and human skin? Do the beetles show an affinity for these surfaces? Dermestid beetles would be a possibility in that case. Note that it is the thorax of your beetles, not the head, that is the lighter color. The head and antennae are not visible in the images. Try for better pictures. Dermestid beetles are an indoor pest.