Well hostis only translates to stranger in the singular, in the plural it only means “enemy”. So any group of foreigners would never be referred to as hostis. The Romans typically referred to groups of people by their ethnic identity. So if you were a Gaul they typically referred to you as such, or Greek, or Celtic. A better word for foreigner is peregrinus. This was also the term that was typically used for foreigner rather than hostis.

As far as citizenship is concerned the Romans weren’t necessarily stingy with handing it out after the social war in the early part of the 1st century BC. In fact a barbarian was granted citizenship if he served in the military for 25 years. So while people who were born with Roman citizenship may have thought it came with certain values, this is not inherently true. This would’ve been the case, however, in the majority of the republican period. In fact Rome has to fight 2 different wars against its allies because of the issue of citizenship. First was the war against the rest of the Latins, who were all in a unilateral alliance with Rome, but they didn’t receive any benefits of Roman citizenship. After this war the Romans extended “Latin” rights to all the cities in Latium. The second of these wars was the aforementioned Social War (91-88 BC), in which Rome’s italic allies rebelled for the exact same reasons that her Latin allies had previously done. The Romans also won this war, but they granted some italic cities Roman citizenship, and they preserved the “Italian rights”

The Romans would also admit entire groups of barbarians into the empire without extending citizenship to any of them. Barbarians could also be admitted to the Empire as one of 3 groups, for lack of a better term. The first of these 3 classes were the dediticii, which was also a class of freedmen in Rome. In regards to barbarians, these were the people who had willingly given themselves up to the Roman state, deditio means to surrender, and were then allowed to settle within the empire’s borders. While the dediticii were usually the lowest class of freedmen, in regards to Barbarians it was the highest class of barbarian allowed to settle within the Empire. The second class were the laeti. Laeti more or less translates as “happy” or “lucky” and may have also been a joke on the part of the Romans. It may have been a joke, because this particular class of Barbarian were those who were captured by the Romans and then settled within the Empire, so they probably weren’t very happy about their situation. The laeti had even less rights than the dediticii. The final class were the foederati, which took on a different meaning in the later empire. These barbarians signed a treaty with Rome to be allowed into the Empire. These foederati were also subsidized by the state, when Rome could still afford to do so. They were obligated to provide a certain number of troops to the army every year, though the dediticii and laeti most likely had to do this as well. They also had more rights than the other classes of barbarians. In addition to this, most barbarians who were admitted to the Empire had to convert to Christianity, or promised to do so in exchange for admittance.

On top of these, there is also Caracalla’s Antonine Constitution. This granted citizenship almost every freeman in the Empire. It’s not entirely known exactly why he did this, but it did increase the number of people who were subject to taxes (though this may have actually been unprofitable in the long run).

Taking all of this into consideration, the “prestige” that came with Roman citizenship probably deteriorated over time, especially after Caracalla granted citizenship to most men in the Empire. Therefore if people who were born as Roman citizens did have any feelings of unease about others being granted citizenship, that sentiment probably died away by the reign of Diocletian.

I hope this answer was helpful, and sorry in advance for any typos I’m currently on mobile.