I would see a lighting specialist at Beacon or similar lighting store for professional design advice Those lights on beam look silly We had beams in our kitchen and ended up getting suspended track lighting where we could focus lights on individual areas in kitchen

the easiest way to light any space is look at which way the globes point, and you can see it in the picture you posted. When that fitting is turned on the light hits the ceiling first and washes down from there. What you need is functional lighting whether you make a statement of the light or let the kitchen do the talking is up to you, the best form of task lighting for you in there would be a 3 circuit track system, allowing you to place and point the light where you want it. And being 3 circuit the same track could have 3 different functional light fittings suspended from the 1 power source.

Thoughts/opinions appreciated and specific recommendations in providing better lighting to the kitchen without running wires through the timber beams. Either fixing some lighting to the wall above the window, or individual spotlights along the beams. Thanks!

You need to focus on task lighting firstly. A down light between your head and the cooktop, and another between your head and the sink. Then either your track lighting or pendants over the island.