Ah. Blackberry. I forgot that is included in the J2ME target devices. That explains nearly everything, although any of my friends who had those blackberries have transitioned since, and now people are just (well played WhatsApp) locked into the service.
The phone number as an id is a very important component to their adoption indeed. So do you posit that WhatsApp's adoption rates being what they are (compared to say Viber which does the same thing) is purely due to first mover?
That's not really an option at all, at least not to your house. At the kLab we have a 15Mbps line allocated for us, but the realities of oversea (well, undersea) bandwidth purchases means we often don't really see that.
Most people not at kLab get mobile data connections that in good areas when it's working well can get downloads between 200KBs up to 1MBps (those are bytes, not bits) depending on the time of day. Up oftentimes is about the same as down. It's not heavily throttled as you see in many other countries. These data plans are also very cheap.
Really, the biggest problem here isn't so much the speed these days, it's that the connection occasionally just stops working altogether.
Rwanda has a classification specifically for technology entrepreneurs. It's a 3-year visa and if you are a qualified software practitioner, I don't foresee you having difficulty getting a permit to start a software company here. They also pride themselves on same-day business registration.
My main concern in this question is that I've heard of a growing concern in East Africa that foreigners are taking jobs/money out of the country instead of investing. From what I've heard, Rwanda sounds perfect, though Kenya has pretty amazing infrastructure too. Kenya is however a lot more dangerous than Rwanda sounds.
I've certainly heard some of that, but I don't think it applies quite as much to tech entrepreneurs -- and I've seen more evidence of that in say, Kenya. If you are coming here to build a software company, I would be surprised if Rwanda's arms weren't opened pretty wide.
At this point, Nairobi has more going on in it's tech scene and certainly a more mature market to sell into, but you are right, it's definitely not as safe and transparent as Kigali.