Nice log Greenatik, I train my potted sativas in a similar way. The difference is that I wind the stem around the outside of the pot rim to minimise contact between plant material and the soil.

I haven't had any problems with insects... but looking at your plant I'd suggest loosening her bonds a little so she can gain a few inches height above the soil, should improve air circulation and remove the leaf litter from the top of the pot. If you want to mulch for water retention use just about anything else eg) peat, coco coir, ground lucerne chaff, fine mushroom compost. Leaf litter provides a great habitat for snails, slugs and caterpillars, all of them like having tender green shoots on the doorstep.