You could test the private key by attempting to sign a message with the public address and then use a separate computer/client to validate the signature.

This would be a completely off chain validation.

Bitcoin would actually help countries avoid this type of problem.

Money leaving russia means that it's currency is weaker. If it did not have a currency (instead used bitcoin) then prices of goods it imports and exports would not go up and down based on the state of it's economy.

I don't think that circle will lead to the absolute centralization of bitcoin but will lead to bitcoin being "housed" in several places that are similar to banks.

I would not agree with your statement, however the DoD does use a large amount of money every year. They get their funding from the US government.

A terrorist organization needs to be able to fund themselves

This is probably an issue with the nodes that multibit is connected to.

Try closing and restarting multibit. If that does not work then reset the blockchain (twice if the issue is not resolved the first time).

If this does not work you should export your keys and input them to a blockchain.info wallet then send a TX to a new address in a new wallet in multibit (if you wish to continue using multibit).

This will likely (if it hasn't already) make it's way into classes that are computer and IT related.

It will likely be a long time until there are separate classes regarding crypto currencies and this is still a very new concept.

The value of the US dollar is the value of the US economy as that is what it is "backed" by.

The english language does not have a central authority.

I don't think that most dictionaries give a sentence example of how words are used.

I think that Bitcoin in places like Africa would be more successful if fiat is not involved.

Most country's currencies are not stable in Africa and holding bitcoin would be relatively safe when compared to holding the currency of an african country.

The issue with LTC is that it does not really add any value that bitcoin does not provide. The same is true for most other alt-coins as well.

The chances are extremely small.

If this were to happen it would likely be due to some kind of attack at your RNG.

There are many more less advanced ways to attack you to attempt to steal your coins. I would personally not worry about this.

The vast majority of users of bitcoin are male. This is partly because most users are very technically inclined and stereotypically this is a male interest.

There was even a thread on this forum that lists the red flags of a potential scammer and one of them is that someone uses a name that is clearly female.

blockchain.info and the blockchain really are one and the same.

Blockchain.info has all of the blocks mined on it's website for anyone to view.

The difference is that blockchain may display a block that gets orphaned prior to it being orphaned.

I would disagree.

A small amount of regulation can be good for any industry. Having to comply with minor regulations can help weed out scammers, which would make the masses more likely to be comfortable with bitcoin.

The scammers are the biggest threat to Bitcoin

People use scripts that monitor addresses of brain wallets and when coins are sent to the brain wallet they will push  a TX that sends the coins to an address that they control

The first country that accepts bitcoin as their currency would actually be giving up power.

Smaller countries would benefit from using bitcoin as it's primary currency as BTC could be more stable then the country's own currency. This is similar to how some countries use the US dollar as their "currency"

Circle is a way that will get the masses to start using bitcoin.

Circle does centralize bitcoin but it does not create a central authority.

If circle is successful then others will create competing services that are similar and will further innovate

Bitcoin is disruptive because it changes the status quo.

Previously it took a long time and a lot of effort to send money from person to person, this was exaggerated when sending money overseas.

Both coinbase and greenaddress would be good to be sure that payment will be received with dealing with high value items.

If you are only selling low value items (a few dollars) you should not worry about double spending attacks as they are generally expensive to execute.