Matey, whilst everyones medical condition is different, the last person I would listen to on motorcycling advice is someone in the medical profession, to them motorcycling is akin to selling your mother to the devil, then sleeping with your sister. I had my first severe back injury about 15 years ago, and another around 6 years ago after a large track accident which resulted in 8 months off work. If I had listened to the medics, motorcycles would have been something that other people did and not me. Apart from that 8 months, I have commuted daily on a Blade, and I get no issues, in fact any medium or long length journey in a car gives me issues, but never any distance issues on a bike. Obviously only you know what you are able to cope with, but a second opinion might be worth thinking about. Just as an aside, my Osteo is a female R1 owner, so they are not all bad!
Like I said that is the least of the reasons... I said before It does not hurt to ride... But there is no way I am going to park my Blade in London for some ass to steal it, so I am getting a banger. I don't mind what bike I ride, once I am riding one!!
I have loads of fun on the Blade but it is a waste for me to ride 30mph, 50 MAX, going to work on a Superbike. It's just really a waste and I can use the money elsewhere...