First of all thank you so much for helping, finnj! I'm getting exactly what I need.
Only one more customization is needed and then it's ready for my site.
I'm afraid that my last wish is difficult to fulfill, but I'm sure it's not impossible.
So, what I need. I need to change the uploading of images. It is too difficult for regular users with so many options. People just need to upload the image without choosing the titles, captions, sizes etc.
I found exactly the right upload system in this plugin: http://perishablepress.com/demos/user-submitted-posts/
I don't mean that the image upload should be changed in the Frontier Post plugin, but I'm wondering how could I customize the plugin for my needs.
Is it possible to take this part of the code from User Submitted Posts plugin and replace the one in Frontier Post? Or would it be too difficult? Since I'm not any good in php, I can't do it by myself.
Finnj, could you also help me with this customization? I'm willing to pay for it.