Sounds like you have it covered, once you do the fluids, valves, and tires.
I'm guessing you cleaned and oiled the air filter when you had the carbs off. Hopefully you removed the caps on the idle mixture screws when the carbs were off so you can fine-tune it.
I'd also shim the cush drive when the rear wheel is off -
https://faq.ninja250.org/wiki/How_to...the_cush_drive
Factory Service schedule for more maintenance ideas -
https://faq.ninja250.org/wiki/Service_Schedule
General Ninja mechanical info -
https://faq.ninja250.org/wiki/Ninja250_Howto