Do you have kids? Years ago there was a company up in Willits that might have been a chrome shop or something on an industrial scale, (don't remember) but it spread some serious toxics that messed up a lot of people. I'd check that out carefully before deciding where to move in that area.
Forestville is a small community a few minutes NW of Santa Rosa. I moved out of that area several years ago but I keep in touch with friends. The Real Estate market is beyond insane. The politics of many locals are almost on par with Berkely. However, it is a very nice place and if you can afford it, you wouldn't regret it.
I can't imagine what is going on in Forestville that would bring someone cross country to work there. If you have to work in Forestville proper, you might live an easy commute away in Santa Rosa, Sebastopol, or toward the coast along the "River" if you need affordable.
That place is a story in itself. There was an unsuccessful attempt to build a TV show around what goes on there. Two-year-alcoholics and just about every female teenager an unwed mother. Guerneville is... Just don't bother making a joke about that Bar called the Rusty Nail. The whole place is like that.
River Road is a beautiful winding two lane unsafe highway that winds through that area. Many accidents and the way locals drive makes it much worse.
Edit to address your specific questions. Gangs- yes in Santa Rosa. There are several areas in Santa Rosa that have serious problems. Corby Ave, Apple Valley, Indian Village and South Park next to the Fairgrounds mostly. Sebastopol Rd is Little Tijuana.
Shooting Ranges: two, assuming they are still open. One is Montana Hawk, an indoor range and gun shop in Cotati twenty or so minutes south. The other is the Circle S Ranch in the country west of Petaluma. Shotgun, Rifle 300yd iirc and handgun. Nothing fancy and you will drive about 45 minutes to get there.
There is also a BLM 4WD Rec area with a shooting range about a couple of hours away. I've never been there. I think it is called something like Cow Mountain.