My experience has been that this is less of an issue with their UX and more of an issue with the stream itself. Once you start following a lot of artist and especially if you download tracks through the download gates, you end up with a lot of noise in your stream. I'm a DJ and I recently had my 3 year old Soundcloud account with lots of my published music and mixes removed because I had some copyright content in a mix. It was a major bummer but having a new account with a fresh stream without as much junk was a silver lining.
We actually weren't using the firehose from Twitter for JustSpotted. That relationship was for Scoopler, our real-time search engine which we shut down on Tuesday. We're using the public APIs for this new site. Basically, everything still rocking.
Right now you can only track one thing at a time but we will be adding the feature to track multiple words soon. There is a hack in the mean time, just use "@wtf word1 OR word2".
A blog is definitely the way to go. I had the same dilemma when I wanted to start blogging about the start-up I'm working on. The vlogging approach is really time consuming and over the last 4 months I've only done a couple to go alongside the blog. Videos are a good way to mix it up and maybe attract people that don't like reading blog. They're also great for sharing with friends on Fb etc, but given the time it takes they're better as an occasional feature to a regular blog. This gives them some novelty value too.