Let's start with a basic premise here: no matter how much they try to repress homossexuality, it will never go away, it will just be in the undergound, still going strong.

Now with that explained, to the questions:

Do you agree with the arguments made by the protesters?

There's two arguments here: I. About homossexuality and disease/death and II. Imperialism.

Let's start with II: It's imperialist for the US government to be flying a pride flag in Jamaican soil?

Yes, but here's the thing: the US flag being there at all could be read as a form of imperialism.

Let's not forget that said flag don't merely represents the US as a country, but a set of values related to being American. Why do you think they put the damn thing on the moon?

The protesters are concerned not with the values represented by the US flag (you know, the pointless wars that created a political clustefuck in the Middle East?) but with the values being represented by the Pride flag.

TL, DR: The protests are motivated by homophobia, not the imperalistic US machine which destabilize whole countries for it's own interest.

So now let's dig deep into I: 'the gays^tm' bring disease and death.

It's bs, clear and simple.

They're just using 'the gays^tm' as a scapegoat for the problems they currently have in this regard, plain and simple.

In some countries on sub-saharan Africa we can see the same shit: they blame 'gays^tm' for the HIV/Aids problem they have even though most of the population there consists of anti-gay christians.

No, it's not the lack of sexual education (which is frowned upon by said christians) or contraceptives (again, frowned upon), it's entirely the fault of 'the gays^tm'.

Aham...

Also, let's address the imperialism question again: why rightoids are so eager to cry imperialism in this case when the entire consolidation of Christianity in Jamaica was a product of imperialism, which goes uncriticized? Strange, isn't it?

Why did this radfem/GC retweet this without any additional comment or context?

It could be either the good old 'the enemy of my enemy is my friend' attitude, which could bite them in the ass in the future if done uncritically, orrrrr on a more cynical note could be just a sign that this specific radfem/GC doesn't give a shit about gay men.

I'll leave which is the case for my fellow posters to decide.