Did I understand this film correctly? Please help

Was Maria merely using Leonard (hence the film's title The Innocent) to get rid of Otto? What was the deal with Maria and Bob Glass? Did Maria marry Bob and have three children with him after Leonard left?

I watched a poor quality version of this film on the internet without subtitles and English is not my first language, so some bits were a bit of a blur to me. However, I did enjoy this film, for being a big Campbell Scott fan. Although I did find it quite amusing and unfortunate that the lead actors had to play characters of different nationalities: American actor Campbell Scott played an Englishman, Welsh actor Anthony Hopkins played an American, and Italian actress Isabella Rossellini played a German.