Honestly no, I don't trust SteemConnect (even though I've used it, hesitantly). It's a big juicy target for hackers. It has absolutely nothing to do with the team behind it or the technology being used - I just think it's an unnecessary risk that users shouldn't be forced to accept to use external websites.

Every time you use your active key, whether to grant authorities for an application or to transfer funds, there's a risk of compromise and funds being stolen. Your web browser is probably the most unsafe application on your entire computer - why would you want to put your active key in it?