I will give a try.
Korea definitely needs support of the US military (the same as all other countries who are in all kind of alliances with USA). It's surrounded by powerfull, not so friendly countries. It's the only way of surviving. This is something I am sure about.
Now, second question I will answer just based on the things that I can see on the internet (it can easily be untrue). I think that the real question actually is: "Are Koreans brainwashed by the West (mostly USA) propaganda or not?" Their propaganda is insanely huge and Korea could be easily influenced by it a lot bc of it's position. It's easier for Koreans to become it since they are kinda "saperated" from the rest of world, like their neighbors are mostly those "not so friendly countries". So it is even the smartest for government to actually make people believe in all this propaganda imo. Also, almost everything Korean I saw had a little bit of this propaganda too. Idk... I will go with "yes, they are liked by Koreans".
Now, you should tell us the truth!
The truth is mostly my truth and what i heard and expirienced, so it might differenciate with someone elses opinion.
A lot of koreans doubt the use of the american military bases. Korea itself has over 9'000'000 military educated men that could be called in, in chances of a war breaking out.
Some even think that america provoces tensions by being placed on korea.
They are open friendly and kind, it is very easy to make friends with americans and they behavior is kind of leger cool. Also are they very faithful when it comes to friendships ( i never dated anyone from the usa, but i am open for anything, (stop this reckless self promotion you idiot))
Now to the negatives:
Many americans (mostly tourists) are ignorant of our culture, are loud, rude and behave reckless.
We have this weird mindset going on that it's okay for koreans to be piss drunk and loud, but not for foreigners.
And americans love to get piss drunk, everyone who ever spent an evening in Itaewon or Apgujeong will agree.
American soldiers are kind of rude sometimes, they break rules a lot in busan, even during quarantine.
History based the american military raped and slanderet a whole city in the south when they arrived in SK to "help them out" So they receive a lot of distrust that has seeped deep into the history of korea.