In reply to gazfellows:
As you say, all mountains / climbs have an element of risk. The ascent of Mont Blanc via the Gouter has particular risks. However, with your own experience and of course that of your guide, you will identify the risks, evaluate them and have actions to minimise those risks.
Firstly, I presume you will be doing warm up / acclimatisation routes first. Leaving acclimatisation aside, if you can do two or more full days ( 5-7 hrs of uphill plus descents ) of UK hillwalking / scrambling in a row you are likely to be able to cope with the physical demands. Get out walking uphill and scrambling ( linking climbing routes ) as much as you can before you go. Then you weill be confident you can cope with the physical demands.
Once in the Alps I presume you will be doing skills development and acclimatisation routes beforehand. These will give you a first hand experience of the mountaineering risks involved and what can de done to minimise them. You will also know whether you are ready for the route ( or if the route is ready for you ). You will know if you are acclimatised sufficiently and have the skills required.
The Gouter route has some specific risks such as, but not limited to, the following:
Risk of stonefall in the Grand Couloir area...
This risk can be reduced by crossing it very early in the morning ( nobody on the route above and ground likely to be frozen )
Only doing the route when the forecast is for low overnight temperatures at the Grand Couloir level ( rocks more secure )
Moving quickly across this short section
Pausing to monitor and evaluate conditions and risk before you cross (you can always turn back)
Helmet
Risk of bad weather...
Only go when you feel confident to move quickly
Careful monitoring of forecast and conditions
Prepared to turn back when appropriate
Appropriate clothing and emergency equipment / procedures
Alternative routes / shelter (3 huts/shelters on route)
Risk of crevasse...
Moving roped together appropriately
Crevasse avoidance
Knowledge and skills for crevasse self rescue
(Actually there are very few crevasses on this route compared to other routes to the summit)
To conclude; Your guide is being paid to make all these decisions on your behalf ( in discussion with you if you wish ) and you can always turn back and try again another time. So my suggestion would be to get as prepared as you can, aim to enjoy the steps towards getting to the summit. By the time you are ready to start the route you and your guide will know you are ready and you can enjoy the challenge, the views, the achievement and the beers!