Flying KQ with 17-hour layover at NBO
 

With a 17-hour layover (arriving 5:50, departing 22:55), I'm planning to spend the day in Nairobi, including visits to the giraffe center and elephant orphanage.
Upon arrival at NBO, can I access the KQ lounge to store my bags and/or take a shower before leaving the airport?
If I do enough enough shopping in Nairobi that I want to check a bag, will checking a bag NBO-JFK be an issue given my full itinerary is DXB-NBO-JFK? (I don't know why this would be an issue, just don't recall ever having done this before.)
Fortunately I'll be in Nairobi on a Friday, when the Massai Market takes place at the Village Market Mall. Is there anything else specifically worth shopping for in Nairobi or at NBO?
Any other recommendations for things to do on an all-day stopover in Nairobi?

Just a warning that, with Friday evening traffic, from Village Market to the airport can easily take the better part of 2 hours. Plan accordingly!

I have no idea whether it is feasible to access the KQ lounge on arrivals and then proceed to exit but I would personally be wary of leaving my luggage for storage at a lounge.
As to checking-in luggage en route at an intermediate point, I have never done it with KQ but I have done it with other airlines and it has never been a problem. Can't see any reason why it should be an issue but perhaps there is somebody with a more direct experience with KQ.
As to what to do on a stopover, you may want to have a look at the Nairobi connection and stop-overs sticky wiki on the Africa forum if you have not already done so.

Definitely try do the elephants right on time and then right to giraffe center before lunch which should leave plenty of time for VM. I would always try get dinner somewhere interesting before heading to JKIA after VM.

Traffic is atrocious so ask the driver to use the eastern bypass if you're still around VM when heading to the airport. If you have dinner in Westlands or close enough to Wayaki Way, take the southern bypass. It's longer (just under 1 hour usually) but shorter and not bumper to bumper.

I enjoyed shopping here https://www.utamadunishops.com and at Kazuri Beads, both are near the giraffes and elephants. I always pack some bubble wrap for wrapping delicate items, but some shops will wrap things for you as well. If you hire a driver for the day, you could keep all the luggage with you in the car. The airport is chaotic and I'm not sure about storing luggage there...

Just wanted to report back about my experience.

First off, KQ business class is perfectly fine, especially when paying US$2,000 to fly DXB-NBO-JFK return when more direct routing on the major airlines would cost at least double (and often triple) that. The seat is perfectly comfortable (lie flat), the service well intentioned, and the food just fine (even on the most elite airlines, it's still airline food; I'm not going to spend a lot more money because the food on another airline might be slightly better). I actually found their multi-course breakfasts between NBO and JFK to be quite good and filling.

In terms of my 17-hour NBO layover, it turns out I have a colleague who has two brothers living in Nairobi. One works at the airport, and had a colleague of his meet me before immigration and make sure I had no issues getting through. (I had applied online for a transit visa, and although I never received an email confirmation of my transaction, I had a print out of my application, including a confirmation number, and I breezed through immigration.) The second brother then met me with a car and driver outside and spent the day ushering me around. This definitely is a great way to do it, but based on my experience I would say that it's not at all necessary. One easily could do this on their own using uber or a private car hire.

I relied on this NYTimes article to plan my itinerary. We stopped for breakfast first, and then made our way to the giraffe center when it opened at 9am, and then made sure to arrive at the elephant orphanage precisely at 11am (it is only open for one hour each day from 11am-12pm). We then had a fabulous lunch at Talisman, and then went to the Maasai Market at the Village Market Mall. (The Maasai Market was the only disappointment of the trip. Maybe I didn't spend enough time or didn't know what I was looking at, but the merchandise struck me as mass produced crap, as opposed to local handcrafted wares.)

Most importantly, I would urge everyone to trust the advice on here about the time it can take to get back to the airport. My ride took over two hours (I'm guessing that Friday afternoon/evening is the worst possible time to do it). Even though I left for the airport more than four hours before my flight time, I was incredibly anxious about making my flight given the number of times we sat for 20 minutes without moving an inch. Fortunately we made it in plenty of time, but next time I do this I'll leave for the airport even earlier.

I'll also note that the KQ lounge at NBO is not particularly impressive. If you have a 17-hour layover, do not plan to spend all of that time in the lounge.