Having a decent working paper isn't expected by any means, but it is great if you can actually have one. Most applications have a spot to attach something like that and you should briefly mention it in your SoP and how working on something has informed your research interests.
I don't know how you would get letters from US professors either. I don't know that they are necessary. If you have letters from research active faculty that have published in the top journals from your own school then I think you would be fine. I would talk to the US professors that visit about their schools and the programs there. Get a sense of whether you would like to apply to those schools and email the professors if you have more questions or when you do apply to let them know the application is in.
You seem very well prepared to do archival accounting research. If behavioral stuff interests you, then I would recommend applying to schools that have behavioral researchers in addition to the archival people. You generally don't officially apply to a "track" when applying to a program. You usually send in all of your information and your statement of purpose should talk about research interests. If you mention professors at the same school that do different types of research, make sure it is clear that you know they are doing different types of research. I have heard professors mention that sometimes they read SoPs and it seems like someone just decided to list all of the faculty from the web site. I think that you would get into higher ranked schools based on a desire to do archival-type research. This doesn't mean that you shouldn't mention other interests, but it is something to consider.
I think you are fine applying to top 30 schools. There is a lot of noise in the process, but you seem well prepared. Just make sure to apply to enough schools that you would be happy to go to and I think that you will do well.