Since price is not an issue, no worries - go for it. I've found that lawyers can only input the data you provide to complete applications. Essentially, you are doing most of the work and they are completing the form(s). Nothing lawyer can do for missing chat records (and other issues) other than craft a short note explaining why missing (again, you tell them; they write what you say). I've helped several folks with applications. I my humble opinion, the key is to have an organized, logical flow of supporting documents of the relationship. Like writing an essay; before you start, create an outline from day one to present and then find the supporting documents to substantiate the events. Provide exactly what they ask for (despite the origin - proxy marriage, notarized documents, translations etc.). Unfortunate on your mistakes on the original filing. Again an explanation letter would work here. I have a friend whos attorney completed the I130 and sent it in unsigned incurring a 6 month delay - had to resubmit. Although comes with high praise check their work before your approval. Best wishes; it will all work out in the end.