You want very easy care so you won't have to be weeding, pruning, watering and feeding because it is hard work on a steep bank like that. Along the bottom edge, I'd plant a few soft, smaller plants that won't require trimming back and are OK to brush against. Many natives are great for tolerating poor soil and not needing to be nurtured or fussed over. Clumps of hardy grasses - enough of each to make an impact, say groups of 5-7 minimum. Perhaps red tussocks (Chionocloa rubra) for their bronze tints, and Silver tussock (Carex comans) for their graceful light green fronds, and Chionochloa conspicua, which is very pretty in flower, (like a miniature toetoe.) Mix in NZ iris like Libertia perigrinans for its bright orange spear like leaves and it will tolerate clay well. Marlborough rock daisy if it is a dry area. A little further back put in that lavender, smaller hebes for flower and scent, and possibly some of the many miniature flaxes which come in a range of colours. There are a few spreading prostrate coprosmas that are great in areas like this too. If you don't like the bronze rambler but it is growing well, think of it as the background to set off something that you like, so perhaps a spiky silvery plant like an astelia will contrast with it and be a feature, or a little bright green hebe, with white flowers would contrast nicely. Behind those, put the feijoas, full size flaxes, corokias, the larger hebes, pittosporums, and coprosmas.

You could lay a nice curved shape garden by the corner of fence and plant layers starting with 2-3 mtr trees at back down to 50-70 cm high plants at front. This will soften the fence line and give you something to look at while on the slab. Something for the kids also like a small structure to play in, on and around would complete a nice family back yard. If you are handy you can make you own small play ground copying parts of a local ground or there are kit sets available. Good luck,

You could install racking for both sides of the room, toys & clothes that aren't being used can go into large plastic containers with lids. The two bikes could be hung from the wall or ceiling. And yes, anything that doesn't need to be there, move it on. There are so many hooks and storage options available that it would be very easy to sort this out and by getting a lot of it off the floor.

My very first thought was to paint the ceiling white. Some colourful artwork would be nice I think. I see you have some blue cushions, so some art with that colour would be helpful to tie it together and also a rug on the floor. What about a lampshade with a shiny chrome stand A tallish plant or two in white or pale coloured pots placed somewhere on the TV wall. I see something else on the back of the lounge suite that looks an interesting colour. Wouldn't hurt to bring that colour into the room too.