Alright, I'm sure this have been covered a lot but I'm new at this and done a little bit of reading, so go easy on me. Yesterday I picked up a bike for my wife! First one she has had in nearly 20 years, so it should be fun riding around with her. I figure this bike will be used for excursions into the city and around the neighborhood. While I'm sure it will be a great grocery hauler I know we'll take them to bars and what not at night. So lights are a top priority for me right now.. or at least I think. San Diego requires that front and rear lights be used after dark, which is a good thing. I figure for rear lights I'll grab some cheaper flashing red lights for both bikes. I mainly have two questions

1) how much power should a front light have? We'll be riding in neighborhoods with street lights most of the time.
2) since we intend to leave our bikes for hours on end as we enjoy ourselves, do you recommend removable lights? I'm leaning this way because I'm wary of someone taking nice lights and us being SOL.

So am I completely off the mark here? Do you all have any recommendations?