Looking for English accent reduction courses (Zurich, Rapperswil)

No need to go on a course; if you want to sound posh, watch all Maggie Smith's films, but in particular this one: Tea with Mussolini

https://www.youtube.com/watch?v=XiSazsOAohs

and keep repeating: "Americans simply don't understand picnics" or "they can vulgarise everything, even ice cream".

But really you should go for the Scottish accent: https://www.youtube.com/watch?v=Avp9aUkM5g0

What do you perceive or is perceived as the standard nowadays? I'm curious...

I think if the OP manage to sound like a BBC news presenter he should be very pleased with himself!

Only reason to use it...

Sarcasm or no, I'll respond as I appear to have touched a nerve. It's still the "standard" neutralish accent but noone is really bother about accent nowadays. Even newsreaders now have regional (gasp!) Accents. The world has not yet ended. Even the BBC lets regional accents have their day!

Standard English usage is the important one, distinguishing between SE and dialects is an important thing to understand. Accent not so much.