So far, the novels released are prequels to the actual TV series, so no real harm in reading them before seeing the series. Discovery is sure to get a DVD release.
True. I wasn't too worried about any spoilers, but I imagine they'd want to avoid writing novels that take place during the shows timeframe so they don't conflict with canon (or vice versa). At least until the show is on for a while and the risk of conflicts lesson.
I figure they'll be a DVD release after a while. CBS wants to make money and once they've made everything the could on their streaming service I have to think they'll want to release it on DVD and Blu-Ray to make more money. After all, even fans who've seen it will probably want to purchase something permanent. It just means I'll have to be patient. I figure it may likely be a few years.