Lots of great info on the main site. Here's the one on sexing them, which should be possible with a turtle at least 4" in size.
http://www.redearslider.com/determining_sex.htmlAs to food: at the size of your turtle, it should be getting more vegetables than protein and shrimp should be a treat nota staple, but you probably know that.
I'd suggest providing lettuce in the morning and letting it stay there, even if uneaten throughout the day. One trick to encourage pellets is to soak them in the water drained from a can of tuna.
Another option for getting better protein than shrimp and vegetables is to make veggie shots:
viewtopic.php?f=8&t=17486That water temp is probably a bit high for an adult RES. and you may want a greater temp difference to encourage basking.
I can't speak to the handling issue, but one thing that may also adjust the reaction to handling is feeding in a separate, small water-filled container. That way he will come to associate handling with food and react more positively. RES have different personalities, though, and it's possible he will never like handling that much.