So, is there any information for how long I can apply after having this 1 year visa?
Yes, the Entry Clearance Officers are given guidance on what the criteria is. The conditions vary from country to country and what the other considerations should be. It's in a document that is not available to the public because it contains country specific information that might get some people upset. If you try to get it using the Freedom of Information Act they will use their national security exemption to refuse.
As a general rule of thumb, people with about 3 - 5 years experience at one expiry can move up to the next step IF they can make a satisfactory case. It's different for each country/individual combination so you can't rely on somebody else's experience to predict your own results.
In some countries like Russia and Ukraine, the ECO will automatically upgrade qualified applications to a longer term and send an advisory to the applicant. Sometimes they will contact the applicant and ask them if they would prefer a longer tenure or not and then collect the fee differential. Most of the time this happens with family visitors who have built up a long, long record of performance. Other cases I have seen are for people who own houses in the UK and like to show up for the social season. Applications that rely on a business premise are rarer. Also in my own experience, most of the time it happens "automatically" (i.e., the ECO decides the applicant qualifies as a matter of course and upgrades the application without asking the applicant). They tell the applicant that next time they have to pay the full fee.
And what happens if I apply for a 10 year visa and the consulate decides that this is too much? Will they reject my application or just give me a visa with shorter validity period?
You can check the box for 10 years and they will duly consider it. If they decide you do not qualify they will issue one at the appropriate expiry and keep the difference in fee (the fee pays for consideration, not for the tenor) because they duly considered it.
Based upon what you wrote, it would not be realistic to jump to a 10 year visa when your current one is 1 year. You're missing too many intermediate steps. But that's a guess. Or they might call you in for an interview to get a clearer picture of your circumstances and issue you a 2 year visa if you qualify.
