accented characters (fonts)

I frequently use non-English words that use accent marks such as Ò or à … it would be very helpful if Scrivener had an easy way to insert these letters (in MS Word, there are key commands – Cntrl+~ + the letter).

That’s already possible. See:

Slàinte mhòr.

To answer my own question – though not a definitive answer – in playing around with another piece of software, I’ve been able to program macro keys that I can use outside of ms Word (which was where I was able to trigger these fonts before) … to get the accented letters – for example, à, À & etc. – it takes four key strokes and there might be a better way to do it, but for now, it might work.