Get a tile cleaning product from Bunnings. Will ensure that the integrity of the tile is not compromised. However, by the look of the stains it seems as though something has been used that was too abrasive, too acidic or that had bleach in it. I do not recommend to keep any product on for an extended period of time. 5 mins max application!

Though I don't know for certain, I think the cotton/linen shades are removable. I wasn't able to determine this by my searches. This could easily be confirmed by making an enquiry to supplier before purchase. Alternatively, a handmade one could be made removable by making shade slightly larger than frame and making ties.

Always seek professional assistance. Be it a colour consultant, designer or a house painter. Always good to bounce your ideas around here as a lot of good advise is given, certainly if you're not sure of where to start. Have a chat to a local house painter, they're the best ones to give solid advice. Paint brands are usually pretty good, certainly the well known ones like Taubmans, Wattyl, Solver, Dulux. Trusted brands been around for decades. Colour consultants are good as they live and breath colour schemes. They can come up with colours to use that the rest of us wouldn't even think of. Terracotta roof is timeless and classic so you're certainly not limited.

I agree with MB Design and Drafting. I rejected two homes based on the building reports alone. It wasn't that there is a lot of work to do or that it would be expensive. It was the fact I was going to have to spend $$$ and time fixing stuff that would never be seen because the prior owners failed to maintain the house properly. I would be spending my first year in those homes organising trades, waiting for people to show up or not, dealing with the headache of unforseen extra problems and cost blowouts. Not to mention I wondered how much unseen damage there was caused by lack of maintenance. Ultimately I purchased a more modest home with less impressive facade and floorplan because it was well maintained and any money I spent would be spent on fun things like decorating or improving fixtures. Plus it already had a major feature I wanted and that feature had been done professionally so it was well worth paying for. It doesn't matter to a buyer how pretty a house is if their heart is broken by a building report that tells them their dream home has a laundry list of boring jobs and unnoticed problems that need attention asap. 9 times out of 10 they will walk on the property than bother renegotiating the price and getting professionals in to assess the $ involved.