The limit of 150 interests is way too small. Of course, some interests appear redundantly spelled several different ways (e.g., backrubs and massage), but those may be weeded out someday to make room for more distinct ones. No round tuits for that any time soon. This account is not so moribund as the journal would seem to show, but mostly I read and sometimes comment.
My friends list policies: if you add me to your friends list, I will most likely add you back, as soon as I notice, so you can read my locked posts, such as they are.
The other people in my friends list are people whom I regularly read; I don't expect them to reciprocate, though. I don't think of my journal as all that interesting, and don't take personally that people are too busy or bored to read my journal.
I really appreciate cut-tags, but I am diligent about reading only some subsets, the largest of which is my mutual friends. That varies by how much time I can spare and what is happening. Sadly, weeks go by when I am too busy to read LJ at all. My pants are perpetually bankrupt.
My locked post policies: I never put anything in my locked posts that is actually secret, but on the other hand, anything that is readable by the world is both extremely public and (can be quite) persistent. The security of Live Journal (and the perviousness of networks of friends and e-mail) means that keeping secrets from interested parties by locking (unless the half-life of the secret is very short) is pointless.
The level of privacy that setting a post "Friends only" gives is that random strangers can't find every word I post via a web search, and that includes prospective employers and the government. (I'm not that worried, or my interests list and friends list, including communities, would not show.) As far as I can tell, I haven't friended a search engine or other bot.
I do like being on friends lists so I can see locked posts, but I shall not be publishing anything I find there without having obtained the explicit permission of the author(s). I don't post much, but if you'd prefer to avoid even that, may I suggest making groups of friends to prioritize your reading time? I had to.
Finding me elsewhere: My other accounts include facebook, LinkedIn, and twitter. LJ doesn't provide a way to list those, though some others are listed below.
I am on AIM, LJ Chat and Skype rather sporadically; my ICQ and Yahoo are pretty much never signed on. I don't think ICQ will delete my number for inactivity, but this way I have a place to remember it. I am a member of several Yahoo groups (mailing lists, really), which keeps that account active.
Facebook, SMS text messages (if you have my cell number or are on my friends list here) and twitter direct messages reach me 24/7, assuming I am awake. Does anyone I know use Loopt?
E-Mails sent via my LJ address do not go to my iPhone, because LJ doesn't sort those out from the many notices it sends me. Fast e-mail requires knowing another address, which I won't list here, to keep spammers from bombarding my phone. Just ask.