Hi Kieran,
I suspect all of us with grafts will have a different answer to your first question! Have you read Ken Pullum's excellent article on this, which goes through the various pros and cons.
https://www.keratoconus-group.org.uk/in ... ransplant/I assume you've gone through the various contact lens options for the left eye - piggy backing and the various types of scleral lens?
For me, the decision to go for a graft over 30 years ago was an easy one. My KC was bad in both eyes, I was wearing lenses in both eyes but only managed to keep them in for the working day by gritting my teeth and trying to ignore how painful they were and how bad my vision in them was! They would come out once I got home and then I was finger counting in both eyes. So I was hugely relieved to be offered a graft and didn't have to think about it. Two years later, I had a graft in the second eye. My graft journey wasn't straightforward - I had various complications, including rejection episodes which were successfully reversed. And I still needed contact lenses for best vision after the grafts, but because I now had smooth, regular shaped corneas my lenses were much easier to fit and comfortable to wear. So I never regretted my decision - without the grafts, I would have had to give up work.
Have you been offered a graft? If so, would it be a full graft or a partial one? I'm assuming you normally manage pretty well with your good eye, though maybe your black dot has made a difference? How much does the poor vision in your left eye interfere in what you see and how much does it affect your day to day life?
I'm a bit like you at the moment - good vision in one eye, but finger counting in the other which has a very old graft, can't tolerate a lens any more and has a cataract. If it would help to talk things through, do ring the KC helpline number.