An all weather outdoor shower is easily done by locating the mixing valve inside the house and use a coupling shaft to locate the handle on the outside. You must use a standard tub type lower faucet (with the pull up to activate the shower) to allow the system to drain out when the shower is done. You also have to make sure everything slopes in direction of the water flow. We live in Bancroft Ontario so winters are well below freezing and we have been showering outside for 3 winters. Only issue we have is the shower head will freeze so we typically remove it after a shower or shower without it on when really cold. The system has worked well and it helps that nothing special needs to be done by anyone. no inside valves to close etc. Just turn off tap and everything drains.

Excuse my duh-ness but i'm having difficulty trying to follow whats going on here. Are these two photos an exact replica of your house and pool ? If not a hasty sketch with dimensions could help a lot. By kitchen wall do you mean the wall behind the bar ? And where is the pool wall ? Are you considering the covered area as being "inside" ? Sorry for all those questions lol Sometimes when you have a design problem you need to turn it inside out or on it's head. If you can't beat it maybe embrace it by making a feature of it : i.e. contrast by having the lightest colored pool surround and a great blue or tile inside and under the overhang, something that will echo the water color ? If you have a great covered area as in photo you'll most likely be spending a lot of time there and it could be soothing to be able to sometimes retire into a darker inside. In my book, 10M isn't small and also contrasting two floor colors doesn't necessarily make a space seem smaller and confined and may in fact even open it up. Could it be that you've thought yourself into a box here ? Sometimes one needs to give it all a good shake up and see how it resettles.

Did you stick it outside? That's what I would've done.

I would clean up first. Especially the stuff growing in the paving. Then get gardening with pot plants and start experimenting with different plants and the positions. See what you like and if you can keep it alive! Our house has the sun setting over the back fence and we've done a few inexpensive things to reduce that issue (most expensive were outdoor blinds around the verandah) but for most of the year we just don't want to be out there. It is hard work to keep the plants going in summer, there is a lot of sand due to the difficulty in keeping lawn alive and it is just bloody hot. So, that's why I'm saying clean up, start gardening small and see how you go before committing to structures that might not address the real issues you have with the yard. Just my 2 cents! :)