Cataracts Treatment

My aunt just had a cataract surgery 2-3 weeks ago, and her eyes have been red for these few weeks. There’s no pain, but she seems worried. Is there any problem?

I have a 7 weeks Boxer puppy who has been diagnostic by my vet today with cataract in one eye, I have few questions;
1) Can a young puppy at this age develop cataract?
2) how long it takes till it (cataract) mature and his eye goes blind?
3) can he survive (live happily and interact with one eye)?
4) what is the possibility the other eye develop a cataract too and when?
5) does cortisone eye drops do anything (Another vet advised to start give it him as it may help in early stages)
he is a wonderful Boxer, I won’t abandon him even if he goes blind coz I believe he would do the same for me…BTW his name is Salvador