Hahaha, I can't imagine a PRO would give you a hard time in this forum! It sure sounds like you've got your hands full. Gosh. I'm in the states. East Coast. In my experience for this area I've worked with a designer most recently who charged $150 per hour. We spent about 6 hours over a 2 day period where she advised & kept me out of trouble getting a color palette together. We went shopping and she helped me chose bathroom tile and plumbing fixtures, kitchen appliances. She's very efficient and we accomplished everything I needed. She billed me $500 at the end of the month and I pd her like that. I know it can get more expensive and complicated when you want them to choose fabrics, furniture etc.

Yes the last pic looks great. Cost is difficult to predict as it would depend on products used etc. Timber thats painted, aluminium, etc. Taking a stab here, say $5000+?

this is one of those jobs that must be done properly but you may be able to help with the final price by asking for plumbers' quotes to include a discount for your labour to dig out all the tree roots and prepare trenches and backfill after the new pipes are installed, especially if you're lucky enough to have 12 months to do the work and start saving..there's not much else that can alter the cost of the plumbers' time and materials but also decide if you're planning any changes to the plumbing as this is the time to make them

I've been playing around with a pantry location. Originally, I was going to move the pantry into the laundry with some custom shelving and cut the laundry space in half. Now, Im thinking of cutting into the study area and building a wall there, and converting the new space into a long and narrow walk in pantry. Either that or build half a wall and put built in shelving in the study. Building the extra wall will reduce the need to cover in the door way that is currently in place and instead utilising it. Thoughts? p.s. this isnt too scale.