The first photo link doesn't work. It looks like it a link to a facebook image somehow. You would probably need to copy it to your computer and then upload it for us to see it. Also, FYI, facebooks links are not permitted on the forum - just for future reference.
It's really hard to see in the photo, but I think your saddle is too small for you and possibly not positioned properly. Height wise, I think you guys are OK. Yes, he needs a bit of weight probably, but hard to tell for sure. He looks like he has sturdy legs I think you'll be fine for general riding. I can't respond about jumping as I have practically no knowledge about jumping.
It would be nice to see a side shot of him with the saddle on and off, and one with you in the saddle as well from the side.
Welcome to the forum!