WattleIdo, I agree with the white paint idea. I was thinking that and some new lights to brighten the place up. Probably replace the carpet, it is fairly worn and orange which is a bit weird and makes the place look alot older. I was thinking some sort of darker grey coloured carpet with a subtle pattern to hide any future stains and marks.
Probably would leave the kitchen and bathroom as is until they stop functioning for what ever reasons.
Like others have said, freshly painted in a white (or close to white) will make it look so much fresher. I would replace the bathroom cabinet because my eye is drawn directly to the crumbling bottom door edge. I would buy chrome tap fittings for bath and vanity. Those coloured ones date the house as much as the tiles but can be changed easily and will make the place look less dated.
The curtains all would be gone if I was renting that place. They are dark and unattractive. I always put up light coloured eyelet style because all you need is a curtain rod and the curtain. No fiddly bits, and so hard for a tenant to damage or pull down.
If the lights are of the same vintage as the tiling, vinyl and carpet, then I'd say certainly replace them, maybe with LED down lights. They are so cheap nowadays. If you don't want down lights, the other thing we tend to do these days is when we swap over a light, unless it is a light we already have, we get the electrician to install batten fixtures. The range of DIY lights that slip over a boring old batten fixture is increasing all the time. For a rental property, it means if a light is damaged, you don't need an electrician. You just buy another DIY fitting from Bunnings (or wherever) and swap it over.
We recently replaced our old horrible carpet and installed nylon grid pattern in charcoal. We used top quality underlay to help it feel nicer underfoot, and it feels as nice as the pure wool carpet it replaced, which was old, stained and had been eaten by moths. I would never buy pure wool again.
This photo shows our wardrobe doors, but you can see the carpet too. It has a sculpted grid pattern in the pile. I think we paid $1440 for three bedrooms in total. We got a very similar carpet in an IP we were selling and used the same company. We don't have any IPs with carpet but I can recommend this company for anybody in Brisbane or surrounds. They are based in Tweed Heads I think. Carpets on the Move.