Do I have to pay for use of Robot ? No, Calculus Robot is distribiuted for free and can be used for free.
How can I specify Lot size for Trades ? Before compiling and running Robot, Lot size for Trades can be specified in Config.h file with constant "const double CConfig::LotSize = 0.01;", after running Robot Lot size can be changed for any following new Trade in file "ConfigurationVaribles.txt" with field "LotSize:0.0100000".
How can I specify Trade Length ? Average Trade Length can be specified in file Config.h with constant "const double CConfig::PercentageOfChange = 0.003;", which with it's Default value results in Trades lenght around 10-12 hours on Average.