Asking for on site talk at this point?
All you can do is ask; the best outcome is they say yes, hear your talk and accept you. The worst outcome is they decline to meet you and then reject you, which is the same as if you don't ask and get rejected anyway. I don't think they're likely to reject you based on you asking politely to meet them.

Apart from that, my only advice is to try not to worry. I remember how stressful the PhD application process is. As they say, good things come to those who wait, but I'd add that good things come sooner to those who are proactive. Good luck!