Adding a layer of rocks, gravel, packing peanuts, other, doesn't reduce or impede drainage, and it doesn't improve it. The soil still retains it's drainage characteristics regardless of whether there is a "drainage layer". If you have a soil that supports 3" of saturated soil (perched water) at the bottom of a container, it will always support that much water - no matter the shape or depth of the container. If you put 3" of gravel or stones - even 12" of "drainage" material under it, the soil will still support the same 3" of perched water. All you will have done: You've reduced the amount of soil in the container and raised the level of perched water so it now sets atop your drainage layer. IF you have a soil that supports a 3" perched water table in a 6" deep pot, and are using a 3" "drainage layer" the soil will be 100% saturated immediately after proper watering. From this, you can see that "drainage layers" are counter-productive unless your only intent is to reduce the total volume of soil in the container (and there are better ways to achieve this) or the soil particles are large enough that they support no perched water, in which case no drainage layer is needed. A 3" layer of saturated soil located several inches above the bottom of the container would be just as detrimental to root health/function as one located at the bottom. Al

Oh hey! Got lost,didn't I? Sorry about that! :) The mass cane aka dracaena fragrans could probably be put right up to the window as well. I know it looks nice in the corner,and may be just fine there,but keep an eye on the yellowish stripe in the middle of each leaf to see if over time it starts fading to green(reverting). That'll be one sure sign that it could use more light. I see no harm in repotting the ficus if it's ready. The way to check that is to turn it over and pop it out in your hand so you can inspect the roots. If there are roots all over the frikkin place,then ya get a slightly larger pot and loosen up the roots(or even clean 'em completely of the old mix)and replant in fresh new mix. Water thoroughly,drain,and you're good to go! If the roots don't look like they're taking over like crazy,it's a good idea to wait until they are before potting up a size because too much mix will hold to much water and not let it dry out as quickly which will lead to souring around the rootball. If air can't get to the roots they will die and that will be the end of a plant pretty quick.

Move it away from the vent. Repot into a cacti and succulent soil mixed with 50% perlite. Choose a plastic pot that fits in the lovely cache pot you have. Feel the trunks, if any of them is soft or mushy, get rid of it because it is rotting and dead. If the trunk itself is dead you still can save the shoot. There are many videos on youtube about how to sepatare shoots from the main plant. Water only when soil is dry halfway down the pot (use your finger or a wooden skewer to check). When you water, do it thoroughly, let water run out the bottom holes, let it drain and then put it back to the cache pot. Never let your plant sit in water and don't give small sips. If you have access to rainwater (or melted snow) use it. Dracaenas don't like tap water as it is hard and may contain fluoride and chlorine that cause browning leaf tips.

There are some sedge/Carex species that might work there if you want a similar shape to Hakone grass. Some like sun and some like shade, some are spreading and some clumping, so I imagine you can find ones that fit your needs. There are quite a range of more sun-tolerant Hostas now, so that might work well also, especially if you chose either ones with leaves a different size, shape, or color than the Hydrangeas. Look at some of the shorter daylilies or shorter Siberian irises which will both have contrasting foliage shape. I find I have to remove dead leaves and old flowers from my daylilies multiple times, but the Siberian iris get old flower stalks removed just once annually and the foliage looks good all season. Both will bloom with several hours of morning sun.