1. Addons
are scripts. The only thing you're accomplishing by having your scripts in macros is that you have to remember to click them all every time you log in or reload the UI. That is literally the only difference between a macro and an addon, other than the character limit in macros -- you have to run a macro yourself, but an addon runs automatically. Making an addon is easy. Just copy and paste your macros into
this page, remove all the "/run" or "/script" prefixes, and click the button to magically turn them into a single addon.
2. I'm not sure whether those are party frames or arena enemy frames, but in either case despite their enormous size, they are rather hard to "read" since there is no spacing between them, and several adjacent bars are exactly the same color. Even just adding a few pixels between the frames would help a lot, and there's no reason for a mage's cast bar to use the hunter class color for example.
3. You didn't mention how big your laptop is in inches, but at the size that image displays on the monitor I'm viewing it on (1920x1080, 24") I'd say you've got a bit of room to stop smashing everything together. Adding 5-10px of space between things like the chat text vs the edge of the screen, the info text vs the action buttons, the player vs target frames, etc. would improve readability significantly. You could also maybe move the unit frames down closer to the action bars and free up more space in the middle of the screen.