Here's some more entries for your disadvantages column:
The disadvantages of Bitcoin:
* It's anonymous and therefore it is hard to trust
* Transactions are not traceable to real world identities and therefore it is hard to trust, and impossible to trace theft properly
* Transactions and organisations are not regulated as banks are, and therefore it is hard to trust
* It is impossible to insure properly against theft and loss, because there are not traceable transactions and anonymous transactions are allowed
Bitcoin itself (I consider it a scarce commodity, like gold) indeed has these problems. However they could be worked around by an entity setting up a secondary system on top of the Bitcoin network (think: paypal handling bitcoins). That way you'd have traceability, auditability, chargebacks and all the features some desire.
Your above criticisms also apply to traditional cash and gold.
* It is not backed by the assets and credibility of a nation, and therefore it is hard to trust
Excuse me, but I find this disturbing. I trust in the value of silver, for example, a lot more than in the value of the EUR, specifically because it is not controlled by any one nation or group of nations who are very likely going to expand the money supply rather than reduce it.
* It is subject to massive speculation, hoarding and other manipulation, and therefore the value fluctuates wildly
True. Bitcoin is still in its infancy. It's already getting a lot better, though: Markets are becoming more liquid and larger every month.
* It's controlled by a cartel of core developers, and the rules could be changed at any time (in this sense it is a fiat currency!)
That's not true. There are various alternative implementations and the thing that would have to be controlled is not the software, but the protocol rules used in the wild. A disagreement on the rules results in a fork of the blockchain. There is then a Bitcoin A and a Bitcoin B and people have to decide which one they use. The users (merchants, individuals, miners,...) decide which ruleset they use, not the developers. Firstly: a fork like that would be bad for both chains and secondly: one chain would likely win (because more people like the ruleset of it better than the one of the other chain and only accept coins from that chain) and we'd have only Bitcoin again after probably quite a short while. So what I'm saying is: the cartel of developers cannot simply change the rules by rolling out an update. For an example look at how hard it was for them to rollout BIP16 (multisignature transactions)... a very positive change, but still it was tremendously hard to achieve consensus of a large enough portion of the rule-setters (all participants, basically)
* Savings are not guaranteed by law as they are in national currencies
Let me paraphrase Alan Greenspan: "We can print as much money as you want, we just cannot guarantee its value". I think this makes guarantees of savings, pensions or whatever a moot point. In addition: saving is in the current scheme greatly discouraged anyway by keeping interest rates artificially low.