There are things to consider Mark...and you'll have to decide if and when they are applicable to your band situation.

First and foremost, insurance for yours (and other band members) instruments, sound system, amps, stage gear, etc...is almost a necessity regarding thefts, especically if any of the equipment is going to be left unattended at a venue, or in a vehicle. Even if people are around at the venue there's no guarantee someone "on the inside" isn't going to abscond with something. (Happened to me years ago at a hotel club that I was assured was under lock and key. Got to the gig that night and our entire p.a. system was gone as well as a couple of synths.)

Secondly, if you are using your own sound equipment (speakers) and some drunk wanders into them, and they fall on him (snd injure or even kill him), like it or not your band is liable. Never underestimate the stupidity of certain audience members where alcohol or drugs may be prevalent.

As someone else mentioned earlier, you may be able to get a rider for liablilty and theft coverage added on to your existing home owner's insurance, or there are some companies that will write you a separate policy. Obviously if you can get it tacked onto your homeowner's insurance it will be cheaper. You can also purchaser special liability insurance for a daily, weekly or monthly rate. You'll have to investigate.