Let's try to help. First, the big drop between seat and bars is normal in racing, even at amateur level. It's so the aerodynamic profile is the best it can be. Riders spend a lot of time on flexibility to be able to achieve a position without getting a bad back. Next, nobody rides a "sportive" bike in races. The position is a bit too relaxed and bike build is different. However well anyone thinks their "sportive special" (sportives are not races, despite what some people may think or want them to be) handles, a race bike is much sharper and responds faster to inputs.
And riders in the major classics may well be seen in big stage races as domestiques or even protected riders. Almost every rider will ride a week to 10 day race at some time during the season. There are as noted the "monuments" (e.g Milan San Remo, Paris-Roubaix, Ronde van Vlanderen, Leige Bastogne Leige). All are 250km +. This years MSR ended up at just over 300km - longest of the big single day races - due to a diversion caused by a landslide.
There are no long climbs - by pro standards - in MSR. Fairly gentle average gradients, nothing much over 5km, and can be taken on the big ring if the wind direction is right. Sprinters sit for almost 7 hours trying not to get dropped, the critical part is the last 25 or so km, Cipressa and Poggio, which are taken fast and are hard because of distance and the wearing down effect of frequent ups and downs all the way. Then the descents are almost as important - Poggio certainly is - it's possible to win or lose in the last 10km that way. Off the Poggio it's a madhouse if there are a good number left in with a chance (as this year), a big fight for position with under 5km left when you hit the main road in to the finish.
Hope all this helps, enjoy your classics viewing!
