Recommendations will all depend on your use of the bike. I use my 2016 FXS almost exclusively for commuting 25 miles round trip. I can't recharge at work, either, but it's not a problem. I can comfortably do two round trips before re-charging, so I just charge overnight at home. If you'll be doing more riding beyond your commute, the DSR will give you higher speed and a lot more range. There's nothing in the 2018 lineup that has me itching for an upgrade, but the small updates are relevant for some people and worth the extra coin.
I have the removable batteries in my bike, but have never taken them out. I had considered charging at work, but never got past the thought of carrying two ~50 pound batteries into work and buying the chargers needed. From what I've seen on the boards here, there are very few people that use offboard charging.
My maintenance costs have been zero so far in 15 months and 6500 miles. The only thing I've done is adjust the belt tension a couple of times in the garage. The next maintenance items I see are brake fluid and tires, but that's a ways off yet.