1)Is there a reason for you to switch over to Tokai at this point of time? Superior or not, i believe it's up to the individual clarity tolerance. As some might not find any difference between a 100dollars lens and a 300dollars single vision lenses. So if Zeiss is working well for you, usually theres not much reason to change. BUT you are the customer so you have the final say in this case but IMHO zeiss lenses are already one of the best you can get. I have a pair of Tokai lens in the past and i see no difference in clarity compared to my cheapo 90 dollar lens(partially i have a high tolerance).
2)Blue light Lenses generally is used to either reflect or absorb a certain percentage of BL emitted from electronic devices. But majority of them still comes from the sun. The lenses basically helps to reduce the glare due to the slight yellowish tinge of the lenses, effectively reducing your eye strain.
But there are other brand of lenses which do not have the yellowish tinge but at the same time able to absorb the blue light,(some people do not like that tinge) so usually i would recommend the other brand which is shamir blue zero whereby it does it's job and not compromising on the colour-perception of the customer.
3)There is no best but probably a preferred choice. For me, i am leaning towards Zeiss, Hoya, Essilor and Shamir. There are more but i usually face lesser problems when i prescribe lenses from these lens manufacturers.
Regarding your first paragraph, Sometimes if there's no issue with your lenses, it's best not to change it. There are afew reasons, but e.g. if they are pro-zeiss, any servicing issue, usually will be easier to liaise with the customer service, but if they dont really order from other brands even though they have an account with them, the aftercare service might not be as efficient.(MY POV). As i said, there's many reasons but, if you are comfortable with them, then just trust their advice!
Hope this helps for now!