What states aside from Texas were ever their own country?

There were only a small handful of states that were actually independent for any amount of time, and they weren't close enough to eachother to truly interact. As a side note, they wouldn't be considered micro nations, as most us states are the same size as euorpean countries. A micro nation generally refers to a tiny political enitity, such as San Marino in italy

You seem to be aware of the four states which qualify for the question, but few of them were contemporaneous to the other during their period of independence. Vermont's nominal independence was in the late 18th century. We almost have overlap for the Republic of Texas, which joined the United States in early 1846, and the California Republic, which briefly existed in the middle of that year, but again, no overlap. Depending what you are looking at when thinking about Hawaii, if just the Republic, again, it was a brief existence in the late 19th century, but even if speaking about the Kingdom of Hawaii, which existed at the same time as California and Texas' brief existence, it was a small island kingdom, and hardly a player on the international stage, isolated as it was.

Given how short California's existence was, it would be surprising if news had even reached Hawaii about her declaration of independence before it was old news superseded by the United States taking over. And while Texas was around a bit longer, certainly they were never in conflict. Having poked around, I can't find record whether they even had diplomatic contact.

So the point is, as stated, your question is very definitely answered in the negative, since only Hawaii overlapped with any of the others, and wasn't warring with either.