Personally in a case like yours, as I did in my case also, I would absolutely seek a second opinion from a MS specialist before having a spinal tap unless you really feel there is a need for one. Unless I've missed something you do not need one to be diagnosed and there really isn't any other information that is to be gained by having it, imo

I have what is called "multiple lesions", sigh. The thing is that counting them isn't an exact science so I try not to get too bent out of shape over it. The count can vary depending on the shot and also who is counting. What I hope to see is that there doesn't appear to be a huge difference in numbers and hopefully none enhancing.

As for steroids, like Cherie pointed out, there are pros and cons. If I'm having a flare that I think will be helped by them and I haven't been taking them very often I prefer to use them in hopes of beating down the damage causing inflammation. Good luck to you. Sadly there are not sure fire answers to most of this stuff.