The aircraft will be fine. I think the security was for the crew. However, I don't think anything other than common sense and normal precautions are required. Having said that, I might go back to the aircraft to run the APU half way through the ten days. (On the Gulfstream it was a recommendation in a salty environment.)
Stay at a decent Malindi Hotel or one in Watamu. Lots of choice.
pm if you want more info.