arran - 9:01 am on Jun 15, 2005 (gmt 0)

What about the PR4+ links? Having them, is it a bad thing or a good thing?

Good - I was just trying to establish if your domain had a penalty or was simply unindexed.

Yesterday I bought a site+content with PR5 which is on topic for a bunch of my non-sandboxed sites ... I wonder if I could place a link for them from these sites, I fear to screw them ... What do you think?

Not sure if you mean linking from your new site to all your existing sites or vice-versa. Should be ok in either case.