Layout of room. Chaise is left facing. Will also post window treatments I like. Everything goes currently in room.

Beautiful tapestry I'd let it be the focal point. As for the pillows/throws-now that's fun! You can bring in all the colors you can find in your tapestry..keep it warm even if the color is considered "cool" and muted..mix it up..bring a lot of different textures-you already have leather which is sleek so bring in something more textured..like knit, rug, embroidered, linen, faux fur, velvet..you can use metallic threads in one or two, to tie in your vases..I don't usually use many pillows but since the sectional is so big..maybe seven? Different shades of brown, gold, rust, green, cream..just play with proportions of the colors and you'll have your variety Throw-same principle-something textured and soft. I'd go with the lighter/brighter color here, from what you've got already-say cream? Or gold. Or rust. Or green:) Look up pillows on flash sales sites like Gilt.com or OneKingsLane.com or Hautelook.com ..they have tons..and it should be Memorial Day sale now, so Just check their return policies etc..sometimes different products have different policies. Or. Head to your TJMaxx..or something along these lines..start checking there..will take some time, don't be in a hurry..you'll put it all together like a nice and very interesting puzzle

No, not necessarily going for coastal look. I have a built in book case with coastal decor, I have collected on my travels. I want to change rug, and chair.. This room was dark before. Want a light and inviting room,,, homey ,, I have young grandchildren....

A sectional is fine, but make sure it's the RIGHT SIZED sectional. Tape out the dimensions on the floor beforehand so you can really see how much space it will take up. Also, because it's dark leather (not a very modern style IMO)and bulky it will visually be heavier and dominate the space more.