I would like to see at least changes in behavior of countries with military access through country with rebels. In my recent campaign Poland had access through Hungary and they went to kill Hungary's rebels every time. Every. Time.
And nope, they don't have an alliance. They simply went to kill some rebels just for fun.
And plz, fix "traveling rebels". I hate to accidentally found, that my small stack got crushed, because some foreign non-separatist rebels just went through my country and my province, where I had a small stack. Make them at least blackflagged.