In regards to your question about the positives and negatives of LinkedIn connections - let me provide you some:
1.) Career Networking - We can all benefit from building a network and LinkedIn can serve that role.
2.) Identification - LinkedIn is not going to work for you if you don’t identify yourself. However, if confidentiality is a concern, and if you are trying to stay anonymous, just be careful to connect with only people you know well.
3.) Search Engine Exposure - You can connect your blogs and other social networks to LinkedIn. Your LinkedIn statuses can be updated when posting to one of those places, providing the opportunity for greater network connections.
4.) Job Hunting - Let say that you are looking for a job, but you are currently employed and you don't want to jeopardize your current position. Be strategic and don’t announce to your connections that you are searching for a job. You can still do your job search confidential by not providing your company's email and phone number.
OTOH, a few "red flags" almost always cause me to decline. Some of those are "the profile looks obviously fake" (these are the ones where the picture is a beautiful blonde woman, and her profile shows no education history, one job with a generic description like "retail" and they have like 5 total connections, and none in common), or "some guy in another part of the world, in a completely different industry, with no obvious sign why there would be any mutual interests, and there's no note explaining why he wants to connect", etc.
That said, if one of you sends me a connection request saying "Hey, this is 'soandso' from HN" then I would almost always accept that.
If curating is providing a benefit, continue. If not, then there's less reason to do it. Me, I decided to pretend to have lots of business friends years ago, but I spend so little time on the site that their status updates don't create much noise.
I don't find much value in the activity.