New minting of the original _bitcoin-1_ would clash with the non-upgraded full nodes.
A new soft-fork-currency is like bitcoin-2, non-upgraders would not notice it has emerged, they will happily accept them (blocks which contain bitcoin-2) as valid blocks.
Soft forks would not violate the former validation rules, it just makes them more narrow (such as, former validation rules _AND_ blocks must contain bitcoin-2 information).

Actual implementation may not be so beautiful one, depending on the available features/space.

Depending on the miners' demographic distribution, it probably works in the same way as the original bitcoin issuance (hashing competition).
Launching a soft-fork-currency will stimulate the new mining competition, it is different from the random coin-creation on the Bitcoin blockchain. It creates scarcity because it will be directly backed by the world's biggest mining facilities (only one), and difficulty to make a soft-fork will ensure it will be done only in a really needed situation.

Miners also can promote the soft-fork-currency by giving some discount for their tx-inclusion service.

I agree with the "segregated witness" part. Although the "block size" will be within the 1MB limit, is it OK to forget the signature data completely? If not, and someone has to save them as archival data, then I rather prefer them to reside in the 1MB blocks.

SFCs are like bitcoin-2, bitcoin-3, ... and so on. Old full nodes can (and would) completely ignore them. But SFC-updated clients will be able to "see" a new currency type such as bitcoin-2.

Recent advancements such as "Segregated Witness" by Pieter Wuille and "Drivechain" by Paul Sztorc showed the power and flexibility enabled by soft forks. But the same technique can also be used to effectively raise the 21M limit, by issuing "soft-fork-currencies" (SFCs) whose protocol rules are the same as those of cryptocurrencies.

For revenue-deficient miners (due to halvings), these soft-fork-currencies have a number of advantages compared with launching a (separate) new altcoin:

• Once implemented, all Bitcoin miners must follow the rules of SFCs, in addition to the original Bitcoin protocol.
• Exactly the same Bitcoin hardware backs the security of SFCs, as those blocks which violate the SFC rules will be orphaned. (same security level with BTC)
• SFC coins can be used to pay tx fees for the Bitcoin blockchain, in the same way as bitcoins.
• Launching a SFC requires miners' unanimous consent, which at some extent prohibits reckless overissuing of SFCs, so moderate scarcity will be achieved.
• The same process of value-creation can be used, with maximally diverse and strong userbase.

My concern is that, in the near future miners' revenue will unproportionally diminish relative to their vital roll in the Bitcoin network. In other words, there will be a point where miners' power is huge but there is not enough revenue for them. This opens the possibility of miners trying to monetize their power through issuing SFCs (soft forks).

Paul Sztorc noted that:
http://www.truthcoin.info/blog/contracts-oracles-sidechains/#bitcoins-limited-government

If miners can create additional revenue streams for themselves, then the above equation does not hold.
Moreover, unlike proof-of-stake coins, bitcoins and SFCs have symmetrical relationship: the blockchain protocol is agnostic of which one is used as a currency or tx fees as long as they have value.

So this "feature" can be used to complement the miners' revenue and possibly prolong the Bitcoin's life span, although the 21M limit will get shaky.

I'm not necessarily convinced that the feature is bad for Bitcoin, but if the miners start to issue SFCs, I'm not certain the ramifications to the bitcoin as a currency. Thoughts?

If Bitcoin goes down hopelessly, those bitcoins will be forgotten and destroyed permanently.

need to lock voting?

I like the #3 by sadface.

I found that the logos are tend to be fairly simple. Decorative things can be added later when necessary.
For example, here is the logo of Monero ("M" in circle + plain font) and Qora (which denotes the same "Q").

I think that the basic shape matters the most and my summary of top candidates is as follows:

#3 (circle + horn)
#10 (circle + ball)
#11 (loupe + 10-point-star)
#12 (circle + tail)
#13 (circle + backslash)
#18 (#11 + #13)

Actually, I was surprised such a cool logo has not been owned by some entity yet (the #3).
It looks like sending a signal that pretty matches with a quasar!  

I agree. Especially the word/sentence order is reverse that is annoying for translation. What's worse, the nuance/ the way of telling is so different that is rooted in culture, which may evoke fatal misunderstandings when expressing in Japanese. 

That's it.
Total of 26 logos.  

-

-

-

-

-

-

-

-

-

-