That is a tough situation. I am in the process of making the move from EasyWorship 7 to OpenLP. Most of our songs came over pretty well but since we have had many different people entering songs over the past few years on 3 different versions of EW, I don't expect the import to be perfect. Any time you migrate programs, expect some level of cleanup. The importer for the most part does a great job though. I still went through all of our song very briefly to look for any that looked obviously off and touched them up in OpenLP. I have also directed my team to proof read any songs added to the service so that we can fix any if needed as we use them. A good example is O Come to the Altar. On EW, I had the line "Jesus is calling" on its own slide, and that is repeated twice in each verse. The imported recognized that as a single line and dropped the second instance so I added it back after reviewing the song. Not a big deal, but just something to be aware of and keep an eye out for. I expected to do this, so I factored in some extra conversion time when considering the move. Even with that, I decided Open LP was well worth it.
Unfortunately, in your case, it is going to have a rough time, as you are not letting it know how the songs are laid out. The importer has to work with what you give it. It is very difficult to write something like that to handle every formatting nuance. I think the only way you are going to be able to fix that is one song at a time by either labeling them in EW and doing the import again, or just going through and fixing them in OpenLP after import. Open LP does make it pretty easy to edit songs so if you go that route. You right click the song, select edit item, then Edit All, that will allow you to go through the song and assign the appropriate verse number as you go through it.
You will also want to take a look at the verse order on the song as well. That is one of the features I love with Open LP. On the edit all, you make sure you only have one instance of the Chorus and it is is properly labeled, then you can add that in the verse order on the bottom of the song edit "V1 C1 V2 C1 V3 C1". But, in the actual song edit, you are going to have that laid out at Verse1, Verse2, Verse3 and then Chorus1. When the song is added to the service, Open LP will display it in the verse order you specified on the song. It makes it very easy for our worship leaders to let me know during service planning on how they preliminarily plan to go through the song. It also makes it very easy to clean up the songs, since you only need to make sure the chorus is correct in one spot.