l just recently bought one from holy funk they have some nice ones at a reasonable price

Looks very nice!

This is very similar to our floor plan (yet to start building) ... same as you we have our backyard to the north, kitchen to the east, dining table in the middle, lounge to the west. And we had the exact same dilemma where to put the couches. We decided on position 1 but in an L shape with a couch along the west wall and north wall. And we will have two arm chairs or ottomans in your couch position 2. We decided on this because it feels more open and didn’t want the TV to be a main focal point. Don’t necessarily want to see the back of the couch either.

it;s unrealistic to expect to be able to squeeze an extra bathroom and wir into such a small space and also add a toilet into the other bathroom.. based on available information the toilet and hall is about 3.5m long but needs to lose at least 1m to allow for a new bedroom doorway and then fit in a shower at least 90cm, plus a tiny handbasin about 60cm and a toilet at least 80 cms (including knee space) to leave almost no standing room for a very skinny adult, there's no leftover space for a wardrobe in the hallway and also need to lose another meter off the existing biw or relocate the whole biw to the other side of the bedroom...and any guest would have to use the toilet in the master bedroom, as there's not enough space in the other bathroom to fit a second toilet ...a builder might do it for you but i would be very disappointed with the result and horrified at the cost for so little...my suggestion moves four doors and updates the existing bathroom by creating a separate powder room and more convenient access to the existing bathroom ...changing access to the linen cabinet makes the living area easier to furnish and there's alternate locations for the heater and ideas for a fresh new kitchen