I would strongly advise avoiding full levels with a pair of robos, they make terrific pairs/groups but it won't take much to set them off and it can be a difficult task to regain the piece again! For a single adult robo I think it would make a fab home as long as you plasticoat the wood if you haven't already and fill the bottom as high as you can with substrate as they love to dig and because the levels don't have walls it obviously means you can't put substrate there.
I would keep the levels where they are because if the robo does take a fancying to bar climbing it means it can't climb too high and so shouldn't hurt itself
As for the ramps, you could buy lolly pop sticks and make banisters down the side of them if you were really worried and a banister around the holes in each level, robos are quite bouncy though and are usually fine dropping/or jumping small heights if they did decide to give it a go.
Overall it does look like it would be lovely for a lone robo, depending on the size of the bar spacing it may be better suited to a robo over 4 months old.