One option for your occasional longer drives would be to rent or borrow a car. If the LEAF would meet most of your routine needs, it might make sense to just rent a car for the longer drives, if the need is fairly infrequent.
I know of two very active people for whom the LEAF is their only car. They are active also on this forum, so they might choose to chime in here.
Having driven my LEAF for about 3400 miles in 4.5 months, I can answer some of your other questions.
I haven't had any problems with power outages affecting my ability to charge here in Southern California. My longest drive on a single charge has been about 85 miles total, but you'll find accounts on this forum from people who have driven about double that mileage by including charging stops of several hours in their trip. At the public Level 2 charging stations, you will add about a mile of range for every 5 minutes of charging, so 5 hours would get you an extra 60 miles.
As far as advantages over gasoline ("ICE") cars, the main ones are that you will be driving using domestic energy that pollutes less than gasoline, both at your tailpipe and considering the entire energy production and transport cycles for electricity and gasoline, and you'll be improving your local environment while sending less money to world regimes that don't like the USA. If you charge over night, you'll leave the house with a full charge every day, and of course, you'll never have to go to a gas station again, unless you need air in your tires. The car is very quiet, allowing you to carry on conversations easily, and it encourages you to feel relaxed and calm as you drive. On the other hand, since you like BMWs, you may also like the instant, high torque nature of the drivetrain and the low center of gravity of the LEAF for spirited driving. I don't charge at work, but that would be a real plus if you can do it. It doesn't sound like you have solar power on your home, but having solar power and an electric car makes for a great fit, for reasons I won't take space for here.
Nobody that I've heard of has had to get parts replaced, except for fender benders, so we don't know about parts costs. The big question mark, though, is about the replacement costs of battery modules. But the battery warranty is 8 years, 100,000 miles, though the specifics of what qualifies as a battery failure haven't been spelled out by Nissan, beyond saying that "gradual loss" of charging capacity isn't covered.
Overall quality is a matter of opinion. Everyone that I've spoken with or read on this forum agrees that the quality of the "carpet" that Nissan uses barely deserves the name "carpet". It reminds me of flocked wallpaper or mouse fur. So floor mats are a must. The paint is good looking, but rather thin and easily chipped if you're not careful around the car. That said, though, I don't have any road chips and only one chip that I caused myself by being careless. Aside from that, though, I find the quality to be quite good, keeping in mind that Nissan had to go for lighter weight and lower cost in the body and materials to keep weight and overall vehicle cost down in light of the cost and weight of the main batteries. The car is not a luxury car by any means. Aside from the extensive electronic displays and the presence of such features as nav, rear view camera, bluetooth phone and audio, XM radio and traffic, Homelink transmitters, and quite a few other features, the car is a mid grade family sedan. Others will call it an econobox and there are threads on this forum where people have taken the car apart and were not impressed with the build quality or the materials. But from the standpoint of a regular daily driver who doesn't intend to tear into the car, I find the quality quite good and I enjoy driving it every day.
I hope that you continue to consider a LEAF seriously.
