I would set
Simultaious Connections to 4 for HTTP and 1 for FTP - this controls how blocks the download is split into
timeouts - leave as it is
Max Sim connections - set to one so it downloads one program at a time.
Under Integration, Uncheck the Check Default Download manager.
Fresh Download has a lot of bugs (esp the 6.70 version) but its the best free one i've found and you soon get used to it.