Seems I was under the wrong impression that ripple was not open source, dunno why.

Definitely a lot of things that I like about what is written down there. Notably:

• Having light clients that run as browser extensions
• Not needing to download a blockchain

Is there a forum topic / page where Ripple is criticised, so I can see some of its disadvantages?

Do you need to have pre-established social connections with people that you trust for settling debts etc?

What happens if your buddy defaults?