I do like the name Hugo- if it sounds good with you surname then it should be fine.
I think the problem with these more unusual boys names is that in the UK other children might ridicule or bully them, but it will depend on where and what type of school your child attends.
I don't believe for one minute that a name makes you homosexual, but certain names do have overtones.
There was a famous very camp, gay English man called 'Quentin Crisp' who was quite notorious some years ago. Perhaps some people might still associate that name with him and consequently, homosexuality. Obviously, little children will not have heard of him but it's just a name that in UK society is often linked to this man.
On the other hand, you have Quentin Tarentino, the famous director, so it does depend on your viewpoint.
I think that traditional king's or saints names like Edward, Henry, William, Richard and James are still regraded in England as 'posh' names that most people like. Or perhaps something like Toby, Rupert, Oscar, Christian or Issac.
But as you have a European surname, then these names may not suit. Unfortunately, the class issue in the UK is alive and well, so I would advise not giving your son too unusual a name, that labels him.
St John is an odd one because as a name it is pronounced 'singen' or 'singon' not phonetically- 'St John' as you would read from the Bible.
Good luck with you choice.