What does the addition of kelp in sushi rice do?

I am a former chef and worked in Japan, the kelp your speaking of is known as "Kombu" is it a dried bull klep from off the coast of North America, and as stated it is used for a flavour and mineral enhancer, is is also used to make "dashi" the japanese soup stock, what you do is soak it in hot water and add the rinsed rice to it and let it cook either on the stove top or in the rice cooker, then you add the seasoned vinegar at the end to flavour the rice to make sushi. Most japanese restaurant will use it, as for home cooks like theonyoung lady it is a bit pricey, here in Toronto Canada, I buy it at a local health food store by the piece, there is a pair of scissor to cut off what you want and it is weight for the price, I get a piece and cut it smaller for my uses.

basically it just add favour to the rice ...

without it you still can make sushi rice.... just that you may not have the unique taste.... anyway , cheap sushi place don't even add this stuff anymore( good kelp is hard to find,to find good kelp : you should smell the sea in them).. they add the artificial kelp favour to the rice ..

nah you do not need to do that.

After you cook stickey rice, you should add vinegar and sugar. It will make your sushi rice a little sweeter but not really for american.

If you go to asian grocery store, you can find the powder for sushi rice. just add it. It contains vinegar and sugar. Even if it is powder, it will work well.

Kelp makes d rice shinier and glossier. And it gves dt dstinct flavor.