But to do so would be theft because the centralized authority who facilitates the transactions has deemed me the owner of the account. No such authority gives people the same right over their BTC addresses.

But what gives the first person the exclusive right to use that address?

So you are claiming that people who dictionary attack brainwallets are not morally or legally responsible (i.e. they aren't stealing)?

Let me clarify that I understand how the asymmetric key signing process works. I am looking from a legal standpoint--how can you assign ownership of a BTC address to a person?

When I obtain a debit card, I have exclusive ownership over the use of the debit card address and the funds of that address because the bank (a centralized authority where the money is held) agrees that I (a person) own them. With BTC though, people randomly generate a private key to use and the person's identity is not attributed to that address in any explicit manner.
How can there be ownership in a system where there is anonymity? For instance, if no bank accounts had names attributed to them and people simply made transactions based on whether or not they had a pass-phrase or key to a certain account then how can someone claim that another person, for example, steals from them?

This question came to mind when thinking about people generating private keys based on phrases like brainwallet.org does. If someone generates a private key with a phrase that happens to already be in use (and has a positive balance) then how is it stealing for the newcomer to move those BTC to a secure address?

Is ownership over an address justified in a homesteading kind of manner in where the first person to use the address is the owner of that address? For some reason that seems unsatisfactory to me.

My thought process is that in order for altcoins to have longevity, their value propositions must be larger than the value that BTC has from the network effect. Currently, many altcoins site that their faster block rates give them a higher value proposition but once third party handlers get involved to speed up transactions to credit card-like speeds, the block rate won't give them much of an edge. The proof-of-work authentication model that BTC uses is costly (energy and hardware wise) but I have yet to see an alternative cryptocurrency (such as Ripple) implement a better system.
It makes sense that LTC/PPC have value currently because the faster transaction times actually gives them value but once third party transaction companies get involved to implement a PayPal-like system to speed up transactions, LTC and PPC will more than likely fall due to lack of innovation.

After waiting for a single block confirmation (taking up to 10 minutes), it is very unlikely that the transaction will be overwritten by a longer, differing block chain segment, yes; however, if your transaction is currently only accepted by half of the miners in the world (before being confirmed in a block) then there is about a 50% chance at that given period of time that a block will be found that doesn't include your given transaction, thus voiding it. It takes significant time to disseminate your transaction through the mining community and when it is, there is nothing that forces the given miners to accept your transaction into their currently working new block. Because of this, it is possible (and very likely if one does not include a transaction/finders fee) that a given transaction could be not successfully added to the chain.

Currently there are no payment processors that insure against such things which is what I was talking about when I suggested a PayPal-like transaction that would do the following:
1. Authenticate the sender and make sure that he/she has sufficient funds.
2. Reduce the balance in the sender's account.
3. Increase the balance in the receiver's account.
4. Confirm the seller that the transaction went through.
5. Proceed to issue a BTC transaction between the sender and receiver on the actual BTC network, making sure that it goes through and resending if it does not.
*Finishing step 5 will take up to 10 minutes but the transaction for the user would be confirmed after step 4, taking only a couple seconds at most and allowing for things such as groceries to be bought in a timely manner.

I have bought a couple small things online which waited for 10 minutes to confirm the transaction. I didn't mind the wait online but if I made more transactions or wanted to do this on the go then the 10 minute wait would be a huge inconvenience.

People buy groceries far more often than they buy cars.

The third category that it proposes are ones with higher value propositions due to innovation. It doesn't mention if a x4 block speed combined with scrypt hashing would be sufficient innovation to overcome the value that btc has accrued due to the network effect.

Imagine if you went to the supermarket and every single person took 10 minutes to pay... The wait would be outrageous. BTC works okay for online transactions at home but fails speed-wise in many instances. This is why I proposed the idea of a debit-like account (that functions similar to PayPal) so that a person can instantly send BTC to another user without the wait (the idea being that the transaction security is handled by the third-party so that sellers don't have to).

I was looking for arguments for the future of altcoins (specifically LTC but also others). Advocates of LTC usually site LTC's value proposition as being higher due to it having 4x the block rate and an ASIC-resistant hashing algorithm. Many BTC advocates say that these changes are not substantial enough.
Addressing the fact that altcoins can have faster block rates--are cryptocurrencies meant/intended to be used directly for quick transactions (such as transactions a person would make with a credit card)? Do you think that third-party 'handlers' will arise to speed up transactions to credit card-like speeds by immediately insuring a transaction and then waiting for several blocks of authentication behind the scenes and holding the sender/payer responsible so that the seller of goods doesn't have to? Such third-party providers would make the block times nearly irrelevant and make direct transactions synonymous with bank wire transfers and not very common for people to do directly. Thoughts?