Phew! First, my material on the topic:

http://alife.co.uk/essays/the_singularity_is_nonsense/

http://alife.co.uk/essays/the_intelligence_explosion_is_happening_now/

Then a few points - which I may add to later.

3 and 4: hardware, sure - that is improving too - just not as fast, sometimes. A machine may find a way to obtain a credit card - or it will get a human to buy whatever it needs - as happens in companies today.

6: how much time? Surely a better example would be: "perform experiments" - and experiments that caan't be minaturised and executed at high speeds - such as those done in the LHC.

7: AltaVista didn't protect us from Google - nor did Friendster protect against MySpace. However, so far Google has mostly successfully crushed its rivals.

8: no way, IMO - e.g. see Matt Ridley. That is probably good advice for all DOOMsters, actually.

Some of the most obvious safeguards are likely to be self-imposed ones:

http://alife.co.uk/essays/stopping_superintelligence/

...though a resiliant infrastructure would help too. We see rogue agents (botnets) "eating" the internet today - and it is not very much fun!

Incidentally, a much better place for this kind of comment on this site would be:

http://lesswrong.com/lw/wf/hard_takeoff/