You have a wonderful space to work with. I agree with suggestion to add a few tables and a sofa table behind the sofa. I would like to see the library built-in reconfigured to only run along the wall shared by the kitchen--so that essentially your kitchen wall has built-ins running all along that wall with the exception of the entryway--you may need to add a few pieces for it, but will be well worth it. As is, the built-ins look choppy. Overall I like your arrangement of furniture with the addition of a few tables end tables and a sofa table behind the sofa; however if you want to form multiple seating areas, I'd divide into two groups to either side of the fireplace. My only concern with that is that you not block the aisles to your french doors. I'd make a clean pathway to the pool with some type of water resistant runner. We were just at a pool party yesterday and even though the kid's dried off you could just see all the wet footprints. How do you entertain? Is it a lot of indoor and outdoor with swimming? Do you serve drinks from the bar? If there is a lot of traffic to you bar, perhaps you could move closer to one of the french doors. Does anyone actually use the bar chairs or are guests more included to stand in groups and chat at the bar?

Sectional looks fine, however, if you find it uncomfortable then by all means start shopping around. I prefer sofa and chairs because the intersection of the sectional's angles never gets sat upon. It's wasted space. You could also get two sofas of the same style and color. You seem to have the room for it. And put an end table with a lamp at the intersection. Just guessing the seating is uncomfortable because the support under the pillow is a frame without any springs.

Okay: This is what I came up with! Of course, the way you use this space is EVERYTHING. I created two separate seating areas - divided by a "dining" area. One being an outdoor sectional which could be around either an additional fire pit, coffee table, or even ottomans. Near the fireplace/TV is a teak set - a sofa, two chairs, and coffee table. It also depends if you plan on bringing a grill onto the porch as well! Below are the exact pieces I used in the layout:

This is an overview of the room. It's messy because I'm rearranging. 🙂