Because my light fixture over the sink is meant to highlight that area, I chose to center it on the sink counter (center line between edge and wall). Mine is a bit more complicated since it's a corner sink, but basically I had the electrician put the box in the center of the counter space below the light. For me that means it's hanging somewhat towards the back of the sink (It's some 42" deep to the corner). For a regular counter that would be about 12 1/2" from the wall. I'd adjust this with the cabinets in mind though if your uppers are only 12" deep. I would keep the line on the ceiling at the same debth, meaning I'd want the fixture to hang in such a way that the pendant cord was even with the edge of the cabinets (did that make sense?) If you have 15" uppers I wouldn't worry about the line aside from having it within the cabinet field. Pendants are typcially 68 to 72" off the floor to the bottom of the fixture. Given your husband's height I'd shoot for the higher number verses the lower so that when he's busy washing dishes it won't be a bother to his eyes :oP

My uppers are 12" deep and the recessed lights are about 3" from the cabinets so they shine directly over the countertops. The kitchen is not very wide and we have a ceiling fan in the center of it. We didn't want to put the lights too close to the fan because of the possibility of strobing. There is going to be about 6" of crown molding so the cabinet doors will clear the rim of the recessed lights. We also put in undercabinet lights because you can never have enough light in a kitchen! We were some limitations in where the recessed cans could go because we didn't want to move the air conditioning ducts that are above the kitchen.

4” cans are plenty for LEDs and get replacement LED bulbs for your halogens too.The rest sounds good to me just remember you need other lighting in the space , ceiling light is just one level.

Will you ever have ceiling fans instead of decorative fixtures? For fans, I'd have them 2' off the wall. In our custom home's secondary bedrooms (11'x13'), we have four 6" LED, 2' from the walls and a ceiling fan in the middle. This way the lights are far enough away from the blades and don't cause the nausea-inducing strobe effect that can happen if lighting is too close to the fans. (It happens slightly in our small 10'x12' office/playroom since we only put two 6" LEDs on the 12' length on either side of the fan.)