LaTeX.org

Springer will do the typesetting, they just want the content from you.

Commands with the @ symbol are special. You need to activate expert mode to use them.

But really, Springer is in charge of styling your contribution. Your contribution is the content.

Fonts are usually embedded in the pdf by default.

Helvetic is a package that shouldn't be used anymore, really.

Have you thought about using tgheros?

Bakomatex is a commercial product and mostly off-topic here.


Back to miktex on a mac ... Can you call pdflatex via a terminal? Command line

Welcome to the forum.

You know you could just input a picture of your letter.

https://tex.stackexchange.com/q/536123/37907
https://texwelt.de/fragen/26268/erfolgr ... t-in-arxiv

Is your download speed usually that slow?

Ask your professor, he might have a copy of a reasonably new version as a DVD-image.

Did you mean to use apalike?
Not lite

Those red boxes mark links in the pdf.
They will not be printed.