Earlier quoted context omitted.
It sounds like you have a feeling that bitcoin isn't good enough, but don't have any actual reasons for it.
"The network has too many fundamental inaccessibilities" Just because I didn't rattle all of these off doesn't mean "I don't have any actual reasons for it". I suggest you ask more politely for exposition next time. The blockchain is huge, and splitting it is ad-hoc patchwork. The network was obviously not designed for such a thing and I'm not really optimistic about it. At this point it takes 6+ days to bootstrap a…
This is only an issue if you're running a full-node. If you want to place limited trust in others, you can use a light client (like Electrum or blockchain.info), which are very easy to set up.
> There is still no easy integration method with extant payment systems
Coinbase and Bitpay are making huge strides in this area, so I don't agree with you that "no one has done it".
> The system of block verification makes it impossible to do truly instantaneous transfers. This is a big one. Double-spend attacks are real, and people want their transactions to go through immediately.
The legacy financial system takes upwards of 30 days for a transaction to truly be settled. The fact that bitcoin transactions can be provably non-reversible after just 1 hour is an enormous technological leap.
> The system is vulnerable to 51%+ attacks
51% attacks will only get more expensive as time goes on. Also, in the event of an attack, there are strategies [1] that can be employed to minimize their impact.
> Mining is prohibitively difficult for the layman.
I don't think this matters for wide-spread acceptance. Most people don't mine for gold, but they still happily use it as a medium of exchange.
[1]: http://gavintech.blogspot.com/2012/05/neutralizing-51-attack.html