There are two different notions here, as indicated in the OP:

- Whether a profile on another site is indeed the same as on this site (and whether his trades there carry any weight here).
- The ratings on the Trust scores here themselves.

On the former, I’d be pretty reluctant to accept a third-party’s site ratings as proof of much, and having to investigate whether the external site’s profile is legit, and is indeed the same as on this site is rather off-putting.

On the latter, Trust scores and in many cases are misused. Being their conceptual nature that of rating commercial TXs that derive Trust upon the person dealt with, there are a tremendous amount of cases where the trust is built either a bunch of very small commercial valued TXs, or things which are unrelated. Look at my profile for example: All my positive Trust scores are not really commerce relates, and are therefore conceptually wrong (*), although I’m trustworthy as hell IRL.

(*) They should probably be neutral, although I personally do not like the use of neutral for something that, again, is not commerce related. Using a feature for commerce related stuff on positive/negative values, but conceptually allowing for other con commercial neutral rating call for confusion, and it would be better to have a system to rate Trust  for commerce and "Trust" (or whatever we want to call it) for anything else, as two different entities.