For a low time pilot there is very little chance to get hired by just sending a CV. Actually this not only true in Africa but even here in the UK people who land jobs on smallish aircrafts, they are usually guys who have been showing their faces and motivation at every opportunity.
As for Bots and places like that you will have to take the risk (as you put it). Indeed if you don't you will join the millions who talked about it but never did it. If you do turn up then you will be up against a much reduced competition and in only a matter of time (can't tell you how long, you understand of course that it varies), you too should be flying commercially (I.e Dosh!!).
Ringing Embassies is a start but not sure it will be very useful.
Most countries will tell you that jobs are to go to nationals first.
If you apply for a visa and mention your intention then it is very likely that you will find your application rejected.
Also should you find a job from home, most employers will ask you to turn up as a tourist as applying for work permit, residency and licences is much easier once in the country.
My gut feeling is that amongts all the low timers who got jobs in Africa, a good 90% found an opportunity once on the spot rather than from home. If you want do it, I think you will have to go for it but quite rightly so, keep on digging infos as it isn't necessarily step to make but a certainly very rewarding one once you got what you wanted.
Good luck