Been playing for a few hours, few questions

Im happy I ended up buying it so far, and was trying to avoid using the internet for questions, but here we are...

Whats the significance of all the radios, lights, and cameras everywhere? Turning them on, off etc? Im gonna guess they have something to do on playing on a higher difficulty and distracting people?

Also, I started as a corpo. If I was to try aborher character, would the starting point be different but the same story?

As for walking vs driving, im trying to walk everywhere to find more stuff etc. Does the car have any purpose other than moving around faster?

Im really just exploring, doing quests and trying to take the game in. Its like a futuristic gta mashed up with outerworlds im finding. Its enjoyable.

Im just hoping it doesn't get too in depth like rdr2 or something? Really just have a few hrs a week to play if that, dont want it to be too complicated. Seeming straight forward and easy enough. Do a mission, progress thru the story, shoot people etc. But all these cameras, computers and stuff I feel like im missing something critical to the game lol.