Many suppliers will put dry clean only on their curtains (including the custom made ones) to protect themselves from people mishandling the fabrics and if there's a block out backing on the curtain then this might not be washable. Linen will shrink if you put it into a hot washer or dryer but as Julia has indicated linen is a beautiful fabric to use if you do the right thing by it - if your wanting linen for the block out use a fabric backing rather than a linen that has a coating and make sure that the block out fabric can be separated from your linen fabric (curtain makers will hate it as it's a nightmare double handling, but if you're going to spend a lot of money on linen and for them to be made, it's not unreasonable to request this.

drawstrings are inside the track and don't need different curtains: simple pleats made with pinch pleat tape and prong hooks should be good with linen and, if your ceilings are higher than 2.4 m you could try hanging the track about 1/3 of the distance from the top of the window architrave to the ceilings eg if the ceilings are 2.7m high the door/window architrave would usually be about 2.1m above the floor leaving about 60 cms from top of architrave to the ceiling so hang the tracks about 1/3 x 60 cms ie 20 cms above the top of the architrave...that should allow quite a bit of saving in the material required and look much better than hung fromm the architrave and, depending on how wide the windows are, make sure the track and curtains are wider than the window so that the curtain can pull to the side to "stack back" and expose the whole door and window ie if the window/doors are 2m wide then try and allow at least 45cm-60cms on each side... btw despite understanding how the curtains are made and having made the effort many times i was very happy to have my latest curtains and tracks supplied and installed by Spotlight and by taking advantage of their regular sales i had the whole job finished for only about 10% above the cost of doing all that work myself!

Such a shame to hide behind sheers. I like seeing out my windows. Just keep your room tidy and close curtains when you do really need privacy.

The only reason it may be difficult to do a full length curtain, from ceiling, is the lack of anchor points for curtain brackets. There is hardly an angle, so the curtains are not going to slide down a slope. In your situation the top windows are a third of the total window space. In my opinion doing curtains on the other two thirds may look odd. With mid century homes with a top window space of maybe a quarter or eighth of total window, that looks fine with lower curtains, your window configuration is different. Get a curtain company in to quote on angled curtains, and look into where anchor points could be positioned.