For a rental, I would look at creating a car park where the front lawn is. off street parking is a bonus in most area, it might also be used as a turn in so you don't have to reverse out of that driveway. And maybe set it up as somewhere to store the wheelie bins too. Also I would take a good hard look at that massive tree in the front corner, and any other trees near the house. The roots may have caused the existing structural problems, and if so would create issues with a new build. Finding a decent property manager and excellent tenant would be my priority though. If you are in a popular location and asking fair money then you may not need to do much. While a buyer cares about cracking brickwork, a tenant won't care as long as it doesn't leak. Maybe defer spending on the home until you have a tenant, in case you can claim the expenditure on your tax- seek professional advice on this one.

to access the power point through a backboard cut a matching hole in the backboard to access the power point and add a small extension cord to have the power in a more convenient location but storage depends on what you need to store but try the PAX wardrobe (1500 wide x 2100 high) with extra shelves plus a freestanding chest of drawers eg Malm 80 wide to leave a small gap at the window wall for the blinds and use wall hung open shelves and don't forget to secure the wardrobe and drawers to the wall...if you prefer the chest of drawers to be the same depth as the wardrobe you could add an extra counter on top of the drawers (Ikea and Bunnings sell custom cut counters in various colours but consider having the chest of drawers and/or the wall shelves in different colour for constrast and matching knobs or handles to doors and drawers

Need a full floor plan and maybe some pics along with what you want to achieve and budget

The part of the home that you have shown, does not appear small. Room sizes are good. The problem is the kitchen in a thoroughfare, but it has plenty of storage. And the wall between sunroom and living. i would seriously look at removing the wall between sunroom and living, check with a structural engineeR. You said you do not want to remove walls, but this is the only way you can increase the size of that room. Maybe keep a supporting post in the middle, and work your furniture around it. Then install of full wall of storage on the dining/laundry wall.