Definitely remove the glass addition. I cant see where the exit door is for that backyard. I would consider centerring the outdoor patio on wherever the view is in your house. Make the patio large enough to fit in whatever it is you wish to do on it; dining, lounging, firepit, hot tub etc. Leave space at the house for plant beds because it always looks funny when the patio goes right up to the house, and it looks like you get enough sunlight in this part of your garden to achieve this.

I would consider hiring a Landscape Design/Build firm, or independent Landscape Designer/Architect to come up with a set of plans for your property because it is quite large, and you should have an end goal to achieve. Good luck!

thanks for your help, it is daunting, so a landscape consultant might be in order.