Very interesting ideas.

In terms of the logo and currency symbol:

• The currency symbol ideally needs to be based from a lowercase 'n' and not an uppercase n. This is because NXT's currency symbol is almost certainly going to be based on the uppercase 'n' and we don't want confusion arising between NXT and NEM because of it.
• The logo must be clean and simple. What it can't have is a huge amount of text trying to cram in everything that NEM has to offer - leave that for the website. All the logo needs to contain is the currency symbol and some colour; it needs to be recognisable.

HERE IS MY SHOT AT DESIGNING A CURRENCY SYMBOL AND LOGO.

Obviously I am no graphic designer but I think it gets my point across. Simple.

• The silver texture may need some changing/refinement, but it conveys the 'silver to NXT's gold' message.
• The currency symbol is easy to write and instantly recognisable as (a) a currency and (b) a brand
• Something which could be added is the word 'NEM' below or on the coin. This would associate the logo with the name.

I hope this is enough to grab myself a stake. Glad to help!