Separate names with a comma.
For blocking porn/other sites on your entire home network I recommend OpenDNS. It's a bit complicated to setup but it's worth it.
You can use OpenDNS without access to your router, it'll just be on a per-machine basis.
Yeah, there are definitely tradeoffs. Doing the journal thing and adding the tips is a good compromise.
Changing your username won't make Google automatically forget the pages it has indexed. It might be worth considering blocking search engines...
You could use OpenDNS's parental controls feature. It works with pretty much everything since it doesn't require installing any software.
I don't know if this is enough data to draw any kind of conclusions from, but I filled it out anyway.